it': 

-1 









] 



/,.iV\.,^.;/' 






THE » 



CLASS-BOOK OF ANATOMY, 



ESIGNED FOR SCHOOLS, 



EXPLANATORY erp THE 



FIRST PRINCIPLES 



HUMAN MECHANISM, 



AS THE BASIS OF 



PHYSICAL EDUCATION 



T7: 

Br JEROME V'. C.SMITH, M. D. 



'* for I am fearfully and wonderfully made ; 




BOSTON: 

ALLEN AND TICKNOR. 

1834. 



-£ d ^ >• 



Entered according to Act of Congress, in the year 1834. 

3y Allen and Ticknor, 

in the Clerk's Office of the District Court of Massachusetts. 



_?^?223fc 



PREFACE 



The object of the following pages will be readily un- 
derstood ; and should the work, in the hands of public 
instructors, be instrumental in explaining to the young, 
for whom it w^as designed, a general knowledge of their 
own curious organization, it ms,^ lead to the adoption of 
such habits in early life as will msure health in youth, 
and intellectual vio-or in ao;e. 

The questions interspersed through the book are far 
from embracing all the subjects adverted to in the sev- 
eral natural divisions of the text : — - they are merely ex- 
amples of the best mode of conducting the study, leav- 
ing it entirely with the teacher to select such parts for 
recitation as he may conceive most advisable. 

Technical words have not been wholly avoided ; — 
such as have been retained, are for the master^ and not 
for the pupil, to aid him in acquiring a more minute and 



VI PREFACE. 

exact knowledge of the science, that he may be the bet- 
ter prepared to assist those who are intrusted to his care. 
Should the volume meet the approbation of those 
who are devoted to the best interests of mankind, it will i 
not have been written in vain. 

J. V. C. Smith. 

Quarantine Ground, > 
Port of Boston. 5 

Jan. 1834. 



CONTENTS 



Page. 

The Bones, — Osteology, .... 2 

The Ligaments, — Syndesmology, ... 45 

The Muscles, — Myology, .... 50 

Apparatus of Joints, — Bursology, . . . 114 

Fluids, — Angiology, ..... 115 

The Nerves, — Neurology, ..... 153 

The Senses, 175 

The Ear, 175 

The Eye, . 205 

Feeling, or Touch, ...... 240 

Smelling, ...... . 240 

Tasting, . . . . . . . 241 

The Glands, — Adenology, .... 242 

The Viscera, — Splanchnology, .... 258 

The Fluids, — Hygrology, ..... 269 

The Skin, 272 



ANATOMICAL CLASS BOOK. 



AivATOMY is a useful science, which explains the nature, 
office, and structure of every part of the human body. 

From remote antiquity, men of learning and persevering 
industry have labored lo comprehend and explain the 
complicated machinery of man, but at no period has the 
subject been better understood than at the present. By 
the study of this science, the condition of the species has 
been ameliorated ; extreme sufferings have been avoided ; 
and in the aggregate, human life has been prolonged. 

On the minds of youth the influence exerted by a con- 
templation of their ow^n physical condition, founded on a 
general knowledge of the situation and functions of the 
different organs, must certainly have a beneficial tendency. 
As they discover the exact regularity of parts; the fteauty 
and harmony resulting from particular combinations of 
machinery, endowed with a high degree of vitality, on the 
action of which, health, life, and happiness, are constantly 
depending, surely, it would be strange indeed if they did 
not fall, in humble adoration before that Supreme Intelli- 
gence which created, and which sustains them in ex- 
istence. 

1 



2 ANATOMICAL CLASS BOOK. 

Comparative anatomy, implies a dissection of the infe- 
rior animals, as birds, fishes, reptiles and even plants, in 
order to demonstrate, analogically, the functions of similar 
apparatus in man. This is an exceedingly useful pursuit, 
and though philosophers have apparently been guilty of 
unnecessary cruelties, it was not from a desire of gratify- 
ing a malevolent disposition ; — on the contrary, all their 
researches have had reference to relieving mankind from 
some of those manifold evils, to which the splendid me- 
chanical organization of the frame is predisposed. 

ANATOMY IS DIVIDED INTO NINE PARTS. 

Os-te-ol-o-gy, which treats of the bones. 

Syn-des-mol-o-gy, '* *' '' li2;aii)ents. 

My-ol-o gy. *' '' ** rauscles. 

Bur-sal-o-gy, " " " apparatus of joints. 

Aii-gi-ol-o-gy, " " of vessels, as veins and arteries. 

A-den-ol-o-gy, " " of the glands. 

Splanch-nol-o-gy, " *^ *^ viscera, as the stomach, &c. 

Hyg-rol-o-gy, '* *' *' fluids, as the blood, bile &c. 



OSTEOLOGY. 

All the bones, in manhood, are hard, and ahnost insen- 
sible, being composed of earth and lime, held together by 
means of gelatin, a kind of glue, secreted by appropriate 
vessels. The substance of the long bones, as, for exam- 
ple, those of the limbs, are compact, excepting at their 
extremities, where they become irregularly larger, and 
slightly spongy. They are classed in the following man- 
ner : — 

r 1. Cylindrical, — bones, as in the arms. 

< 2. Flat, — bones, as in the shoulder blades. 

(3. Irregular, — bones, as the ribs and thoso of the skull. 



ANATOMICAL CLASS BOOK. t3 

THEY ARE FURTHER SUBDIVIDED INTO, 

First, — hollow bones, possessing marrow. 
Second,— flat bones, or those destitute of marrow. 

Before arriving at about the age of twenty, the ends of 
the bones are considerably spongy, and imperfectly united 
to the main shaft, — and, therefore, termed epiphises, from 
two Greek words, meaning to grow upon, but afterwards, 
they become firmly united. 

The names of a majority of the bones are very arbitrary ; 
some of them, however, have their appellation from a fan- 
cied resemblance to some object; others, are named from 
their shape, connexion, or supposed, or real use. 

Every cavity, hole, or prominence, even to the burden 
of the science, has also a name, — a knowledge of which 
is a key to the parts, either directly in contact, or lying in 
the immediate vicinity. 

Protuberances are termed processes, and are generally 
the points of attachment for muscles or ligaments; — the 
first being the moving power, and the latter, the bands 
which keep the ends of any two bones in juxtaposition. 

j1 natural skeleton is one, the bones of which are held 
together by the original ligaments. Remarkable speci- 
mens of these kinds of preparations are common in mu- 
seums, and cabinets of curiosities. 

An artificial skeleton, is one^ the individual bones of 
which are united together by wires. 

In the human skeleton, there are two hundred and fifty- 
two separate bones. Those who labor hard, have some- 
times an extra number, which form near the joints of the 
thumb, fore finger, and toes. They are called sesamoids, 
from their resemblance to the seed of the Sesamum plant. 
They are useful in increasing the power of the muscles 
wherever they grow. 



ANATOMICAL CLASS BOOK. 



THE SKELETON IS DIVIDED INTO 



First, — the head. 
Second, — the trunk. 
Third, — the extremities. 



FIRST DIVISION. 

There are fifty-five bones entering into the composition 
of the head, by including thirty-two teeth. 

EIGHT BONES IN THE SKULL. 

One OS frontis, — above the eyes, constituting the forehead. 

Two ossa parietalia, — making the sides, above the ears. 

Two ossa temporum, — or temple bones. 

One OS ethmoides, — or sieve-like bone, lying between the brain 

and root of the nose. 
One OS sphenoides, — being the bottom of the skull, nearly 

concealed. 
One OS occipitis, — at the lower and back part of the head. 

FOURTEEN BONES IN THE FACE. 

Two ossa maxillaria superiora, — the two making the upper jaw. 
Two ossa malarum, — or prominent cheek bones. 
Two ossa nasi, — one each side, making the arch of the nose. 
Two ossa lachrymalia, — just within the angle of the orbit of 

the eye. 
Two ossa palatina, — in the back part of the roof of the mouth. 
Two ossa turbinata, — within the nostrils. 
One OS vomer, — the partition in the centre of the nose. 
One OS maxillare inferius, — the under jaw. 

THIRTY-TWO TEETH. 

Eight incissores, — front, or cutting teeth ; — four in each jaw. 
I Four cuspidates, — eye teeth, two above and two below. 

Eightbicuspides, — or small double teeth, with two cutting points. 
^ Eight molares, — grinding teeth. 

Four sapientiae, — wisdom teeth. 



ANATOMICAL CliASS BOOK. 



IN THE TONGUE. 



One OS hyoides, — shaped like a capital U, and situated at the under 

and back surface of the under jaw, and above the protuberance 

of the throat. 
Four concealed bones of the ear, collectively termed, 
ossicula auditus. 

Two mallei, malleus, — faintly resembling a mallet. 
Two incudes, incus, — or the anvil shaped bone of the ear. 
Two stapedes, stapes, or stirup, — almost a fac simile of the stirup 

of a saddle. 
Two orbicularia, — or round bones, but considerably smaller than 

a mustard seed, and the smallest bones of the skeleton. 



SECOND DIVISION. 

FIFTY-FOUR BONES OF THE TRUNK. 

The spine, or back bone, is constructed of twenty-four 
blocks, called vertebrae, — of which there are 
"Seven cervical vertebrae, — or joints in the neck. 
I Twelve dorsal vertebras, — oi johits in the back. 
I Five lumbar vertebrae, — being larger joints,' in t'le loins or 
small of the back. 

TWENTY-FIVE BONES IN THE CHEST, OR THORAX. 

One sternum, — or breast bone. 

Twenty-four costae, — or ribs, the seven uppermost are the true, 
and the five lowest, false, or floating. 

FIVE BONES OF THE PELVIS. 

Two ossa innominata, — or nameless, being the broad hip bones. 
One OS sacrum, — being the foundation on v/hich the spinal 

column rests, of a pyramidical figure, with its base upward. 
Two ossa coccygis, — the extreme lowest point of the sacrum. 

SIXTY-FOUR BONES OF THE UPPER EXTREMITIES. 



In the C Two claviculce, — collar bones, 
shoulders C Two scapuIcB, — shoulder blades. 

1* 



ANATOMICAL CLASS BOOK. 

In the arms, two ossa humeri, — between the shoulder and elbow. 
In the C Two ulnce, — on the under side of the fore arm. 
fore arm, c Two radii ^ — on the upper edge. 

THE HAND IS DIVIDED INTO 

C The carpus f — or wrist. 

< The metacarpus^ — palm of the hand. 

( The jjhalaiigeSj — bones of the fingers. 

Os naviculare, — boat shaped bone, 2 

Os lunare, — moon shaped bone. 2 

Ossa carpi, or\ Os cuneiformej — wedge shaped bone. 2 

wrist bones, I Os orbiculare, — round, or nearly so, bone. 2 

eight in eachV Qs trapezium, — a geometrical figure. 2 

wrist. ^ Os trapezoideSj — resembling the last bone. 2 

Os magnumj — so called because the largest. 2 

Os unciforme, — being hooked. 2 

Ossa metacarpi, — ten metacarpal bones, or roots of the fingers 

constituting the palms. Five in each hand. 
In the fingers — twenty-eight phalanges, — finger bones. 

SIXTY BONES OF THE INFERIOR EXTREMITIES. 

In the thighs, two osso. femoris, — thigh bones. 
In the leg, two patellcB, — knee pans. 

two fibuIcBj— outside bones of the leg. 

two tibicB, — or shin bones. 

THE FOOT IS DIVIDED INTO 

First, — tarsus f — or instep. 

Second, — metatarsus, — fijundation bones of the toes. 

Third, — phalanges, — the bones of the toes. 

f Os ca/d5, — heel bone. 2 

^ , . \ Os astragalus, — making part of the ankle joint. 2 

. , J Os cuboides, — square bone. 2 

or instep. \ ' ^ 

J Os naviculare, • — boat shaped bone. 2 

[ Ossa cuneiformia, — wedge shaped. 6 

Ossa metatarsi, — five bones, foundation of the toes. 10 

In the toes of each foot, fourteen bones, or phalanges, — 28 

Eight bones, the sesamoides^ in the thumbs and 

great toes, though not always constant. Total. 252 



ANATOMICAL CLASS BOOK. 



Fig. 1. 




A front view of the male 
skeleton. 

HEAD AND NECK. 

a, The frontal bone. 

b, The parietal bone. 

c, The temporal bone, 

dy A portion of the sphenoid 

bone. 
e, The nasal bone. 
/, The malar, or cheek bones. 
g, The superior maxillary, or 

upper jaw. 
hj The lower jaw. 
i, The bones of the neck. 

TRUNK. 

a, The twelve bones of the 

back. 

b, The five bones of the loins. 
c,d, The breast bone. 

e.f, The seven true ribs. 
g, g, The five false ribs. 
h, The rump bone, or sacrum, 
i, The hip bones. 

UPPER EXTREMITY. 

a, The collar bone. 
6, The shoulder blade. 

c, The upper arm bone. 
df The radius. 

e, The ulna. 

/, The carpus, or wrist. 
0-, The bones of the hand. 
hy 1st row of finoer bones, 
i, 2nd row of fin«;er bones. 
ky 3d row of fing;er bones. 
I, The bones of the thumb. 

LOWER EXTREMITY. 

fl, The thigh bone. 

by The knee pan. 

Cy The tibia, or large bone of 

the leg. 
dy The fibula, or small bone 

of the leg. 
e. The heel bone. 
/, The bones of the instep. 
g, The bones of the foot. 
hy The first row of toe bones. 
i, The second row of toe 

bones. 
ky The third row o* toe bones. 



ANATOMICAL CLASS BOOK. 

Fig. 2. 




Ji hack view of the male 
skeleton. 

THE HEAD. 

a. The parietal bone. 
h, The occipital bone. 

c, The temporal bone. 

d, The cheek bone. 

e, The lower jaw bone. 

NECK AND TRUNK. 

a. The bones of the neck. 
h. The bones of tlie back. 

c, The bones of the loins. 

d, The hip bone. 

e, The sacrum. 

UPPER EXTREMITY. 

^ a, The collar bone. 
6, The blade bone. 
Cy The upper bone of the 
arm. 

d. The radius. 

e, The ulna. 

/, The bones of the wrist. 
g. The bones of the hand, 
/j, The first row of finger 

bones, 
t, The second row of finger 

bones. 
/f, The third row of finger 

bones. 
/, The bones of the thumb. 

LOW^ER EXTREMITY. 

a, The thigh bone. 

hi The large bone of the 

leg. 
c. The small bone of the 

leg. 
dj The heel bone. 
e^ The bones of the instep. 
/. The bones of the loos. 



ANATOMICAL CLASS BOOK. 9 

THE CONNEXION OF BONES. 

When united witli one another, in a way to admit of 
motion, the union is termed diarthrosis. Bones united in 
a manner admitting of no motion at all, are said to be 
connected by synarthrosis. And when they are joined by 
the intervention of anv substance, it is called a union by 
symphysis. 

The round head of the thigh bone, rolling in its deep 
socket, is an example of the moveable connexion, or 
diarthrosis. All the bones of the head present a union 
by synarthrosis. In the racking, or twisting motion of 
the vertebrse of the spine, we find an illustration of the 
last division ; between ^very two bones, there is an elastic 
substance to keep them from coming in contact ; this is 
symphysis. 

STRUCTURE. 

All the large, round bones, particularly of the arras and 
legs, are hollow, for two purposes, — viz. 1st, because 
they are stronorer for being hollow ; and secondly, they 
are store-houses. The marrow is not placed in the cavi- 
ties to keep the bones from being brittle, but to supply the 
system with food when the stomach cannot, or does not 
perform its digestive office. 

During a long course of sickness, we take little or no 
food; — but as nutriment must be provided, to keep a 
proper quantity of blood in existence, — where does it 
come from^? Under such circumstances, the marrow, 
which has been in store from the hour of birth, for such 
an emergency, is now carried from the bones and convert-, 
ed into blood. When that has been exhausted, then the 
fat, wherever it exists, is next taken, — till the body be- 
comes almost a skeleton. 

This is the reason a sick person hecomes poor and lean. 
A scanty supply of food, leads to the same result, hence 



10 ANATOMICAL CLASS BOOK. 

horses and other animals s.re poor^ because they are partly 
nourished, by converting a part of their own bodies into 
food. As soon as the stomach is abundantly supplied 
again, and is able to pursue its accustomed labor, the 
marrow and fat, which were borrowed, are all returned 
and packed precisely as they were before. 

BONES OF THE SKULL. 

The head is divided, in the first place, into rramw/w and 
face. 

It is a curious fact, that no two heads are shaped pre- 
cisely alike; indeed, there is nearly as much diversity 
in this respect, as there are expressions of the face. 
During the early periods of infancy, the bones are so 
flexible, that the skull may be moulded into various forms, 
without injury to the brain. Many barbarous nations, 
from immemorial time, have practised the art of changing 
the natural shape of the heads of their children, either to 
give them some characteristic of the tribe to which they 
belong, or to render them more beautiful, according to 
their rude conceptions of that quality. Observation on 
the natural differences presented in the skull, first gave 
rise to the study of craniology, which was refined upon, 
till it has finally resulted in the modern science of phre- 
nology, 

Calvaria^ is a term to express the top, or convexity of 
the head. The forehead is the sinciput^ and the back 
part, the occiput. 

FOREHEAD. Os frOuHs. 

Having remarked that the skull is composed of eight 
bones, it is only necessary to describe them individually, 
in a very general manner. The os frontis is a single 
bone in the adult, though in infancy it was in two pieces. 



ANATOMICAL CLASS BOOK. 



11 



Though thin and delicate, it is in two plates, whose flat 
surfaces have between them a porous space, called diploe, 
where the blood vessels are safely lodged for nourishing 
it. Over each eye, it throws out a protuberance, marked 
by the eyebrows ; — and within the orbit, a thin sheet- 
like process juts backward, to support the brain from 
pressing on the globe of the eye. Between the two plates, 
on a vertical line with the nose, and just between the 
arched ridges, the two plates recede from each other, so 
far as to leave a large cavity, — \\\e frontal sinusy which 
freely communicates v.-ith the two nostrils, although a par- 
tition, extends from the nose up through the chamber. On 
this apartment, seems to depend the strength of the voice. 




Explanations of Fig. 3. 

Front view of the single 
bone constituting the fore- 
head : a, a, marlv the place of 
the frontal sinus, or vocal 
cavity ; 6, the temporal 
ridge; c, {he nasal process, 
where the bones of the nose 
are joined ; e, e, the external 
angular processes /, /, the 
orbitar plates, above the eye, 
to sustain the brain. 



It is a drum-barrel, in effect, being for the purpose of 
reverberating the sound, by which its sonorous power is 
increased. While suffering from a severe cold, the char- 
acter of the voice is changed, and it is usual to remark 
the person talks through the nose. This alteration, how- 
ever, is to be imputed to the closing up of the passage, 
between the nose and sinus, which wholly prevents the 
sound from penetrating the only spot in which its volume 



12 ANATOMICAL CLASS BOOK. 

or tone can be increased. Snuff takers, by the practice 
of a vile habit, very much impair, and in protracted cases, 
completely ruin their voices, by obstructing the canal. 

WALL, OR PARIETAL BONES. — Ossa pavietalia. 

These are on one side convex, and concave on the 
other, and of a square figure. They lie on each side of 
the head, above the ears, and sustain the office of walls : 
small holes are discoverable through one or both of them, 
through which veins return blood to the great canal with- 
in the skull. 

OCCIPITAL BONE. — Os occipitis. 

Of all the cranial bones, this is the strongest, thickest, 
and most compact. It needs to be so, inasmuch as many 
large muscles on the back of the neck, are inserted into 
it. Its shape is very much like a skimmer, having one 
large hole in it, about an inch in diameter, through which 
the spina! marrow passes out from the brain, on its pass- 
age down the spine, — hereafter to be noticed. After 
these remarks, it will be inferred that its locality is at the 
back and lower part of the skull. 

WEDGE, OR SPHENOID BONE. — Os spJienoides . 

Being entirely concealed, unless the skull is turned 
bottom upwards, some difficulty is found in learning its re- 
lations. Nearly all writers have compared it to a bat, 
with wide spread wings. Through it, many nerves and 
vessels pass out ; particularly the optic nerves, and those 
which supply the teeth, often so painful, in the under jaw. 

TEMPLE, OR TEMPORAL BONES. Ossa fcmporum. 

On these bones, there being one on each side, the 
ears are fixed. They stand between the osfroniis,parittal 



ANATOMICAL CLASS BOOK. 



13 



Fig. 4, 




Explanations of Fig. 4. 

a the thin squamous portion 
of the temporal bone, joining the 
skull, on a line with the top of the 
ear; 6, the zygomatic process, 
which meets the cheek bone ; c, 
a cavity in which the lower jaw 
is articulated ; c?, the external 
opening of the ear ; e, the styloid 
process ; /, the vacinal process ; 
g-j the mastoid process. 



and splicenoid bones, — reaching a little way up the tem- 
ple. In one part of these irregularly shaped bones, the 
splendid apparatus of the organ of hearing is contained, 
which will be fully explained in the proper place. Here 
is one quite prominent process, called the masiGid, which 
may be felt behind the ear, to which the muscle is fixed 
that brings the head forward, as in bowing. 

SIEVE, OR ETHMOID BONE. Os ctJwiOldeS. 

Because it is perforated with many holes, like the top 
of a pepper-box, or sieve, it has received its present name. 
It lies horrizontally, on a level with the eyes, — being 
over the nose, and has the front lobes of the brain resting 
upon it. Through the numerous orifices, fine threads of 
nerves, the olfactories^ pass into the nasal cavities, to 
constitute the sense of smelling. 



SEAMS OF THE HEAD, OR SUTURES. 

All the bones of the head are interlocked by ragged 
edges, called sutures. When one over-laps another, as in 
the case of a part of the temporal, over the parietal bone, 
it is termed di false suture. All the true sutures are zig- 
zag lines, seen on the top and sides of the head. 
2 



14 



ANATOMICAL CLASS BOOK. 



One of these lines, reaching from one ear to the other, 
over the top of the skull, is the coronal suture^ — so called 
because an ornament was placed there, by the ancients. 
The OS frontis meets the ends of the parietal bones to 
make this suture. 



Explanations of Fig. 5. 
a, a, the coronal suture ; 
h, sagittal suture ; c, the 
lambdoidal suture; d, d, 
ossa triquetra, small, rag- 
ged bones, occasionally 
found in some skulls, lyinsj 
in the last nientioned su- 
ture; e, e, portions of the 
temporal bone, overlapping 
the walls. 




On the back of the head, the occipital bone is united to 
a portion of the temple, and the wall bones, by the lamb- 
doidal suture, — which has its name from its resemblance 
to the Greek letter L. 

Between the parietal, or wall bones, exactly on the 
highest point of the arch of the skull, on a line with the 
nose, and, consequently, equidistant from both ears, is the 
sagittal suture, — taking its name from a fanciful resem- 
blance to an arrowy lying between the bow and string. 

There are several other sutures, but it is not very im- 
portant to be particular in their description. At birth, the 
pieces composing the head, are small, and imperfectly 
formed. As we increase in growth, the bones also in- 
crease in circumference, till their edges finally meet and 
form the suture. 



ANATOMICAL CLASS BOOK. 15 

When infants labor under a dropsy of the brain, the 
accumulation of water is often so great, that the head of 
the poor child is enormously enlarged. Such a vast col- 
lection could not be contained in the head, if the bones 
had been united. Being only slightly attached at differ- 
ent places, or, perhaps, not at all, the membranes on the 
inside, are put uponlhe stretch, and the bones offering no 
resistance, are actually pressed out of place. An enlarge- 
ment of the head never takes place, after the sutures are 
formed, though there may be a collection of water in the 
cavities of the brain. 

In preparing the skulls of animals for a cabinet, the 
mode of opening the seams oi sutures, that the shape of 
each bone may be seen, it is usual to fill them with dry 
beans, perfectly full, and after having been placed in warm 
water, they swell and pry the whole apart. 

From infancy to the tenth and twelfth year, the sutures 
axe imperfect ; but from that time, to thirty -five and forty, 
they are distinctly marked ; but in old age, they are near- 
ly obliterated. 

Blows should by no means be given children on the 
head, either by the hand, as in boxing the ears, or by sticks, 
ferrules, and the like relics of the old and obsolete mode 
of school-government. The entire character and destiny 
of a child may be altered by a rap on its half-formed skull. 
It is not only exceedingly dangerous, but criminal, to be 
instrumental in giving a blow that may produce such im- 
portant changes in the brain. 

THE BONES OF THE FACE« 

For the sake of order, these are separated in those 
constituting the upper and lower jaw. A minute descrip- 
tion of the thirteen bones of the upper jaw, would be fatigu- 
mgi and altogether unnecessary ; yet some of the princi. 



16 ANATOMICAL CLASS BOOK. 

pal characteristics of a few of them, will assist the student 
in obtaining a more exact knowledge of other parts. 

UPPER JAW BONES. — Ossa maxilloria sujperiora. 

Many irregularly shaped small bones are uniied to the 
upper jaw, — as the j^a/a^e, vomer ^ 6lc. The upper jaw 
is in two pieces, on the arch of which are situated the 
teeth, in pits, called alveolar sockets, because they some- 
what resemble the cells of honeycomb. Just above the 
angles of the mouth a hard protuberance is felt, where 
the cheek bone is met by it, which is hollow. Nearly 
half an ounce of fluid is sometimes secreted in it, in cases 
of severe inflammation, arising from diseases of the teeth. 
Not unfrequently the roots of the eye-teeth protrude quite 
into it. The name of this cavity is antrum. Its use, in 
common with the one described in the os frontis, is to as- 
sist in strengthening the voice. 

CHEEK BONES. — Ossu maUirum. 

These stand between the last mentioned protuberance 
and the outer angle of the eye, contributing to the forma- 
tion of the orbits. 

BONES OF THE NOSE. — Ossa nasi. 

Two bones, which are merely convex, slender pieces, 
about an inch in length, meeting in the middle, form an 
arch, which thus enables the nose to resist hard blows. 
The partition is one bone, vomer, so called from its re- 
semblance to a ploughshare. Sometimes it is twisted 
more towards one side than the other, — giving a crooked 
or one sided nose, which materially influences the ex- 
pression of the face. 

Within each nostril, there are two distinct bones, called 
turbinated, because rolled up like the folds of a turban, 



ANATOMICAL CLASS BOOK. 17 

but far more like a roll of parchment. They are thin and 
porous, and wound up in the manner we find them, to oc- 
cupy less room. On them is spread out the olfactory 
nerves, in the form of a gossamer-web. By this contriv- 
ance, surface is gained, without occupying too much space. 
The turbinated bones in a dog's, lion's, or tiger's nose, 
were it possible to spread them, would present a broad 
surface, it is supposed, equal to several square feet; — but 
by being rolled, like a scroll, they can be packed in the 
narrow canal of the nostril. Man, not being designed to 
be dependant, particularly on the sense of smelling, has 
small internal nasal bones : — quadrupeds, however, are 
wholly guided in the search and choice of food, by this 
sense ; hence the complicated apparatus, so much superi- 
or to our own. These turbinated bones are liable to dis- 
ease, and are the seat of tumors called polypus of the 
nose. 

TEAR BONES. — Osstt Lackryinalla, 

There is one in each orbit, the size of the fingernail, — 
having a groove to conduct the tears into the nose. 

PALATE BONES. — Ossu palcdina. 

Quite on the back part of the roof of the mouth, these 
jut backward, towards the throat, having, in life, a cur- 
tain or valve suspended to them, which prevents fluids 
from rushing into the nose, in the act of drinking. Usual- 
ly, accompanying the misfortune of hare lip, these bones 
are wanting,— ^ which accounts for the want of distinct 
articulate sounds, in such persons. 

LOWER JAW BONE. — Os maxlllare inferiora. 

All that is particularly interesting in this bone, will be 
discovered in the plate, in which a vast many muscles will 
2^ 



18 ANATOMICAL CLASS BOOK. 

be seen, connected with it. There is a canal, the size of 
a knitting needle, running through it, from one angle to 
the other, traversed by a nerve that gives a twig to the fang 
of each tooth, as it passes along. An artery also makes 
the same circuit, supplying the teeth with blood. 

BONE OF THE TONGUE. Os htjoidtS. 

It is situated in the muscles of the neck, quite in the 
upper and back part of the throat ; its existence would 
hardly be suspected, were it not felt by pressing with the 
thumb and finoer. 



Explanations of Fig. 6. 
a ?>, merely indicates the places where the 
arms, or processes o( this bono, are united to 
the body, a, a, the arras. 



Its shape is much like the under jaw, or the letter U, — 
having the diameter of a dollar. Besides being the origin 
of the tongue, moving up and down, as the tongue is 
moved, it serves another important office, of keeping the 
mouth of the windpipe open, like a hoop in the mouth of 
a sac. 

BONES OF THE EAR. — Ossicula auditis, 

Eachof these, the ^/^a/tel/5, inciis^ stapes, and os orhicula- 
re, are minutely described in the article on the sense of 
hearing. 

BONES OF THE SPINE. — VertchrcB. 

Twenty-four bones, similar in shape, but varying in size, 
laid one aihove the other, are collectively called the spine. 
Processes, or arms, extend out on each side, on a line with 
the limbs; and one projecting backward, is the spinous 
vrocesSy which gives the name to the whole chain. These 




ANATOMICAL CLASS BOOK, 



19 



points are the levers, by which the muscles move the 
whole, as a column. No one vertebra can be turned on its 
axis, but the entire series admit of a twisting movement, 
as demonstrated in all the attitudes which the body as- 
sumes. On the backside of the body of the blocks, the 
union of the three arms forms a ring, — and the twenty- 
four» present a canal, through which the spinal marrow 
passes down, giving off nerves between every two bones, 
to go to the ribs and muscles on the sides. 




Explanations of Fig. 7. 

This shows the connexion 
of the Mocks or vertebras, 
constituting the backbone, or 
spine. All the hnes, indicat- 
ed by figures, from 1 lo 24, 
indicate nerves, which come 
out between the bones, from 
the spinal marrow. Fig. 9 is 
the place of the stomach ; 20, 
15 the liver; 24, the kidneys; 
18, the spleen ; 23, the mem- 
9 brane, around the border of 
'-^'i which, the intestines adhere ; 
•^IS 11 and 12 is the bone called 
19 c;5 sacru??i, which, by being 
prolonged in quadrupeds, is 
—24 the tail. Man, being upright, 
"22 the bone is short, and curved, 
and thus holds up the organs, 
""1^ which, by their weight, 
-.13 would otherwise have a ten- 
dency to fall through the bot- 
tom of the pelvis. 



20 



ANATOMICAL CLASS BOOK. 



Those of the neck are less confined than those of the 
back or loins, in consequence of the processes being more 
horizontal ; otherwise there would be an inability to car- 
ry the head towards either shoulder. 

Between these vertebrae, there is an intervening sub- 
stance exceedingly elastic, convexed on both sides, — be- 
ing thick in the centre, and thin at the edges, which are 
analogous to cushions, to prevent a sudden jar in our 
movements. These are the intervertebral subslance, rath- 
er compressible, yet elastic. After being in an erect po- 
sition considerable time, the superincumbent weight 
presses them down thinner, — so that a person is shorter at 
night, after fatigue in walking, than in the morning, after 
the intervertebral pieces have restored themselves to their 
original condition. 

Explanations of Fig. 8. 
This is an accurate drawing of one 
of the bones of the spine, at the 
neck : a, is the body of the bone ; 
fe, the spinous process, Or handle, 
which gives the name of spine to 
the whole column; c, c, the trans- 
verse processes, to which the mus 
cles adhere, producing motion ; d, 
cf^ round holes through the arms of 
the bone, for safely lodging an ar- 
tery, which carries blood to the 
brain; e, e, the upper, and f. f, 
the under surfaces, which nvake a joint with the blocks above and be- 
low it ; g, the hole through w^hich the spinal marrow, or pith of the 
back, passes, in safety from the head, through the whole chain of 
twenty-four vertebrse. 

A person becomes round shouldered, as the expression 
is, in consequence of the elasticity of the front edge of 
these pads being overcome. A permanent stoop or bend 
of the back is the result. Old age, also gradually 
weakens the elastic power, and therefore aged men are 
often crooked, infirm and shorter, than in their youth. 
Distortions of the body, producing deformity, are refera- 




ANATOMICAL CLASS BOOK. 21 

ble to the want of spring, or proper elasticity in these 
cushions. 

The topmost of all the bones of the spine, is called the 
atlas, because it supports the head, as Atlas was fabled to 
support the globe. It is a ring of bone, without a body, 
which distinguishes it from all below it. With the skull, 
it forms a joint, allowing the head to move forward and 
backward, but in no other manner. 

Joining the atlas, is the dentatus, or tooth-like bone, 
having its name from the resemblance which a particular 
portion of it bears to a tooth. In a full grown man, the 
process is about half an inch high, above the body of the 
bone, — and smooth, jutting up into the atlas. Around 
this pivot, the head rolls. If, by any sudden jerk, the head 
is thrown too violently back or forward, the dentatus may 
be forced from its place, — which would be a dii>location, 
or breaking of the neck, in popular language. When 
criminals are executed by hanging, the process is common- 
ly torn from its place, presses on the spinal marrow, 
which, on its way down the back, passes by the side of it, 
and death immediately ensues. 

All the remaining twenty-two separate bones, of which 
the spine is constructed, are called, simply, vertebrae. 

RIBS AND BONES OF THE GHEST CostCB. 

Twentyfour ribs, seven of w^hich are in contact with 
the spine, behind, and the breast bone in front, form the 
thorax or chest. Each of the ribs has a regular joint, to 
allow the chest to be enlarged and diminished, in breath- 
ing : — a vulgar notion exists that males have one rib less 
than females, — owing to the circumstance of one of them 
having been taken from the sideof Adam, for the creation 
of woman : — the number is exactly alike in both sexes. 



22 ANATOMICAL CLASS BOOK. 

BREAST BONE — Stemum. 

The sternum^ or breast bone in the front wall of the 
chest, is narrow, and spongy, not far from an inch and 
quarter wide and ten inches long, — reaching from the 
throat to the pit of the stomach. 

Several pieces of bone are joined together to constitute 
it, — but the lowest point, which is flexible, is the most 
interesting. It can be felt with the hand. It is float- 
ing, as it were, in the flesh, being flexible and yielding 
to pressure. As we advance in years, it becomes os- 
sified, — and if distorted or forced from its natural place 
in youth, produces the most painful and alarming conse- 
quences in age. . 

If, for example, a person when seated, bends the body 
habitually forward, it eventually bends the point of the 
sternum inward, where it will finally remain. The conse- 
quence is, — the capacity of the chest is diminished, and 
diseases of the lungs, among a catalogue of other maladies, 
may result from it. Children should be warned of this 
liability to disease, before a habit is formed that is formi- 
dable when confirmed. 

This never becomes solid like other bones, even in ex- 
treme old age. Between its perpendicular sides, as seen 
in the plate, and the front end of the rib, a strip of carti- 
lage is interposed, a kind of substance which is familiarly 
known by the name of gristle. The bony wall therefore, 
over the heart and lungs, is decidedly the weakest part of 
the frame. 

There is a radical defect in the seats of all the school- 
rooms in this country. There should be a convexity be- 
hind, to fit the hollow of the back. The seat would be 
more comfortable, and prevent the bones of the chest 
from being cramped down and binding the digestive 
organs. 



ANATOMICAL CLASS BOOK. 



23 



Fig .9, 




Explanations of Fig. 9. 
A the place where the collar bone is 
joined ; C where the first rih is articulated ; 
c, d, 6, /, g, show the number of pieces 
which are united into one : the ensiform 
cartilage, or tip of the sternum, — bent out 
of place, very frequently, to the great det- 
riment of the individual, is marked h. 



Very small children, in schools, become excessively 
weary, after sitting a little time on stiff benches — are 
sleepy, and can scarcely be kept awake. This is nature's 
mode of seeking relief from the pressure and gravity of 
the chest, which is confining both bones and muscles. 
They should certainly be permitted, either to have a re- 
cumbent posture, which is thus indicated, or they should 
be kept but a very little time in one position. Malforma- 
tion of the bones, narrow chests, coughs, ending in con- 
sumptions and death in middle life, beside a multitude of 
minor ills, have often had their origin in the school-room. 



BONES OF THE LOINS. 

Five of the last vertebrae, which are the largest and 
strongest of the spine, contribute to the formation of the 
loins or lumbar region. 



24 



ANATOMICAL CLASS BOOK. 



Fig. 10. 




Explanations of Fig. 10. 
This is a drawing ot one of 
the lumbar vertebrse, — in the 
small of the back, in common 
langua(;e It is much larger, 
and contains considerable more 
suhstance than those of the 
back or neck ; — and it re- 
quires to be so, as it necessarily 
supports the weight of the body 
above : a is the body ; b b the 
the surfaces by which it forms 
a joint with the block above : 
ecu. similar surface, to meet 
the one below ; d d the side 
arms or processes, to which the 
strong muscles of the back are 
fastened. 



BONES OF THE HIPS. — Qssa lunominaia. 

Three bones, the os sacrum and the two ossa innnminata 
or hips, are so united together as to form a kind of horizon- 
tal ring ; within this ring, many important organs are found : 
on the outside of each of the broad, thin hip bones, a 
deep socket is seen, in which the heads of the thigh bones 
are articulated. 



Fig. a- 




Explanations of Fig. 11. 
This is a drawing of the lower 
part of the hip bone, or os in- 
nominatum, in which is seen 
the head of the thigh bone, tied 
into its socket, by a short round 
cord, to keep it always in place. 
Were it not for this curious 
provision, by a thousand un- 
guarded movements, the hip 
would be thrown out of joint. 
a is the membrane which cov- 
ers the joint ; b the cord that 
keeps the bone in its socket ; c 
the socket in the hip bone ; d 
a rim of the socket, to deepen 
it, and/ the thigh bone head ; — 
e a binding ligament; 6 the point 
of bone on which we sit. 



ANATOMICAL CLASS BOOK. 



25 



BONES OP THE SHOULDER. ScapulcB, 

Lying horizontally, between the top of the breast bone 
and the tip of the shoulder, above the joint, is the clavicle^ 
or collar bone, shaped something like an italic s. Its use 
is to keep the arms from sliding forward, towards the breast, 
and it is also useful in sustaining burdens, as when a basket 
is carried o;» the shoulder. Its name is said to have been 
derived froiu its resemblance to an ancient key. 

Fig 13. 
2 314 6785 r.;.. 

Explanations of 
Fig. 12. 

In this cut i'^ seoii 
9 the union of the 
shoulder-blade, col- 
lar bone, breast bone 
lO-ind the shoulder 
joint. These are 
detached from the 
body, hence the 
'11 view is a front one. 
A portion of the col- 
lar bone of the right 
side is seen also, — 
all the others being on the left side. The iigures from 1 to ll, indi- 
cate the ligaments which keep them united, when the muscles are 
di-sected away. 

Skouldcr blade is a familiar name of a thin, broad, 
triangular bone, behind each shoulder, termed scapula. 
At the highest angle, a hooked process stands out, which 
makes a roof, as it were, over theshoulder joint, to defend it 
from violence by the pressure of burdens. At its root, and 
necessarily on its underside, is a depression, called the 
glenoid cavity, in which the head of the shoulder is 
articulated, to make the joint. The shoulder blade does 
not toucli the ribs, nor has it any attachment with any 
other bone than the clavicle, belonging to the chest. It 
lies on a cushing of a muscle, and is moved in various 
directions in every motion of the arm. If the arm is raised, 
carried either forward or backward, down or up, the mo- 
3 




26 



ANATOMICAL CLASS BOOK. 



tion of the shoulder blade may be distinctly felt through 
the skin. 



BONES OF THE ARM. — Ossa Humeri. 

Os humeri and os hrachii are names given by the books^ 
to the arm bone. There is nothing particularly interest- 
ing in its anatomy. At the upper end is a large ball, that 
rolls in the socket of the shoulder blade ; and at the other 
extremity it is flattened, to receive the fore arm, with which 
it makes a ginglymus or hinge joint, admitting only of two 
motions, flexion and extension, similar to motions describ- 
ed by a door, swinging on its hinges. To this bone, a 
principal part of the muscles are attached which produce 
the movements of the limb. 



Fig. 13. 




I 



Explanation of Fig. 13, 

Short ligaments of the elbow 
are here demonstrated : the 
wonder is, how the elbow joint 
can ever be dislocated, without 

2 entirely mining the whole ligja- 

mentary arrangement. The 
4 figures from 1 to 4, not only 
give the locality of each liga- 
ment, but even the figure. 



BONES OF THE FORE ARM. RadH et UIucB. 

Two bones are in the fore-arm, between the elbow and 
wrist, lying side by side : that on the upper side, on a 
line with the thumb, is the radius, so named from its re- 
semblance to the spoke of a wheel. It is sometimes termed 
the manubrium manus, or handle of the hand, because the 
hand is fastened to its lower end, and its upper one has but 
little or nothing to do with the composition of the elbow 
joint. The radius rolls to and fro, carrying the hand with 
it, while its fellow, ulna or cubit, so named because it was 



ANATOMICAL CLASS BOOK. 



27 



used for a measure, is curiously articulated to the elbow, 
but does not reach the hand. 

On these two bones, a vast number of perplexing mus- 
cles take their rise, which produce the multitude of short, 
quick or strong motions of the hand and fingers. 

When tho palm of the hand faces backward, it being 
supposed that the arm is pendulous, by the side, it is 
called pronation. When it faces forward, the thumb be- 
ing outside, it is supination. Those muscles which pro- 
duce these movements, are 'pronators and supinators. 

BONES OF THE WRIST. — Osstt Carpi. 

Eight little bones, whose shapes cannot be well describ- 
ed, placed in two rows, form the wrist. On the back side, 

Fig. 14. 



Explanation of Fig. 14. 
....^,1 This diagram shows the connexion 

of the little bones of the carpus or 
/; wrist, with the two long bones of the 

fore-arjn. 1 the ulna ^ 2 radius; 3 

a scaphoides; 4:lunare; 5 cuneiforme ; 

"-— e 6 2}isifor?ne; 7 trapezium; 8 trape- 

4 ziodes ; 9 magnum. The letters 

••"—6 mark the ligaments which tie ihem 
'"~^5 together. 

10 




they are arched, actually reminding one of irregular sized 
stones, so put together as to resemble a piece of masonry. 
On the inside, they make a canal, through which the ten- 
dons of the muscles glide along to the fingers. 



28 



ANATOMICAL (LASS; BOOK. 




g 



Explanation of Fig. 15. 
Another plan of the bones of 
the wrist, sljowinsj them placed 
in two rows. This is a back 
view of the carpus of the rioht 
hand, a the boat shaped bone; 
b the half 7710071 shaped ; c the 
wedge shaped; d the pea 
shaped; which make the up- 
per row, joining the fore arm. 
in the second row,aie the four 



ot!ierr>, which are united, by a joint, to the palm of the h;'nd. 

Their names are naviculare^ lunar e, cunciforme^ orhifv- 
larc, trajjczitim, trapeziocles^ magnum, and vneiforwe. 



BONES OF THE PALM. 



- Metacarpus. 

A detailed account of the shape and size of the bones 
of the metacarpus, or palm, would seem to be unnecessary, 
as every person can ascertain their number and relations 
by feeling bis own hands; tbe plan, however, is inserted. 



Fig. la. 




Explanation of Fig. 16. 
Four metacarpal bones, side by 
side, precisely as they are placed, 
and of the true shnpe, forming the 
palm of the hand, are seen in tliis 
figure. The metacarpal bone of 
the thumb is seen in Ffg. 17, 
marked a. 



ANATOMICAL CLASS BOOK, 



29 




b --. 




Explanation of Fig. 17, 

There are but three bones in the thumb, which 
are larger than those in the fingers, because it was 
designed to oppose them, and therefore possesses a 
structure quite different. To these three, five mus- 
cles are attached, a, b, c, are the three, but it should 
be recollected that a really belongs to the meta- 
carpus, so that the phalanges of the thumb are two. 



Only two bones exist in the thumb, but there are three 
in each finger, — collectively called phalanges, being four- 
teen in number. 



Fig. 18. 




Explanation of Fig. 18. 
Twelve bones, as exhibited 
in this plan, constitute the 
a fingers of one hand. They 
are separated from each 
other, that the exact form of 
the extremities of each may 
be seen, a the first bone of 
the litte finger, b the second, 
c the third : the same letters 
point out the three, also, 
composing the index, or for© 
finger. 



30 



ANA'JOiMICAL CLASS BOOK. 
Fig. 19. 




Explanation of Fig, 19. 
Here is presented a back 
view of all the bones of the 
hand, as they are connected 
with the eight little bones of the 
wrist. Each bone is so distinct- 
ly represented, that a very 
young child may understand 
the arrangement. 



Explanation of Fig. 
20. 

All the bones of 
the arm, fore arm 
and hand, are here 
exhibited in connex- 
ion, with reference 
to impressing it on 
the mind, after hav- 
ing read a short des- 
cription of the indi- 
vidual parts of the 
upper extreuiity. a 
is the head of the arm 
bone, niliculaled to 
the shoulder; b the 
joint or elbow, form- 
ed by the ulna and 
lower end of (he arm; 
c the shaft of the os 
hwiiieri or arm ; d 
the radius or handle 
of the hand, united, 
solely, to the wrist ; 
e the xdna^ which 
alone forms with the 
arm, the joint. 



ANATOMICAL CLASS BOOK. 31 

BONES OF TflK INFERIOR EXTREMITIES. OsSfl Fcmovis. 

First, the os fcmovis, or thigh bone, is the largest and 
longest in the skeleton : indeed it needs to be, as it sus- 
tains the entire weight of the whole body. The ball, by 
which it is articulated in the deep socket of the hip bone, 
appears to be at the end of a branch, standing out at a 
considerable angle from the shaft, as seen in the engraving 
of the skeleton. This is the Jieck of the fcmoris. Its 
lower end or condyle, is quite large, to make a part of the 
knee joint. All the muscles assisting in running, walk- 
ing, or dancing, are variously connected with it. 

bom:s of the leg. — Tihicz, 

Tibia is the scientific name of the shin bone, because 
it was thought to look like a pipe. United with the con- 
dyle of the thigh bone, assisted only by the knee pan, the 
knee joint is formed. 

At the ankle, it is admirably fitted to the astragalus ^ to 
permit flexion and extension of the foot, as in walking. 
A piece or splint, called malcolar process, slides down by 
the side of the joint, to increase its strength. The pro- 
cess may be felt, being under the skin like a knob, on the 
inner side of the ankle. 

This joint is very securely arranged, to prevent luxa- 
tions : as it merely moves in two directions, backward and 
forward, — nothing short of a degree of violence that in- 
jures the bones, can materially affect it. Beside its lig- 
aments, the tendons of many muscles contribute to its 
security, strength and perfection. 



32 



ANATOMICAL CLASS BOOK. 

Fig. 21. 




3 52 

Explanation of Fig. 21. 
These three plans show how the two bones of the leg are united 
above the ankle joint — 1, 2, 3, 4, 5, 1, 7, 6 — mark the ligaments 
which bind them so firmly. 

Outside of the tibia, is a long, slender bone, the Jibula^ 
lying on the side of the head of the tibia, but having 
nothing to do with the knee joint; — it passes down past 
the ankle joint, giving the same security to it, that is af- 
forded by the maleolar process of the tibia, on the inside. 
Between the two bones, all the muscles, and they are 
numerous, arise, which go to the foot and toes. 



BONES OF THE INSTEP 



Ossa Tarsi. 



Five bones are found in the tarsus or instep, one of 
which is nearly all given to the heel. An arch is formed 
by the other four, similar to the wrist, giving a convexity 



ANATOMICAL CLASS BOOK. 
Fig. 52. 



33 




Explanation of Fig. 22. 
By this diagram, the skeleton of the foot will be clearly under- 
stood, even without the aid of the bones. T\'?enty-six bones are 
here so curiously e^rouped together, that an arch is made between 
the heel and ball of the great toe : — a, shows the five bones of the 
metatarsus ; d, e,/, g, and h point out the fi^'e bones of the instep or 
tarsus ; and b, c, and i, indicate the phalanges or toes. 

to the top of the foot. On the under side, in the sole of 
the foot, all the flexor mtiscles of the toes are found. This 
structure conduces to the elasticity of the step, and the 
weight of the body is transmitted to the ground by the 
spring of the arch, in a way to prevent the injury of nu- 
merous organs, by a sudden jar. Each one of them has 
a specific name, viz. as calcis, the heel ; astragalus^ being 
part of the ankle joint, named from its likeness to a block 
used by the Greeks, in playing a game of chance ; ciihoides^ 
or square bone ; naviculare, the boat shaped ; and cunei- 
forme^ or the wedge shaped bone. 

As in the hand, between the instep and toes, is the 
metatarsus^ in which are five bones, placed like the sticks 
of a fan, to be articulated with the first row of the bones 
of the toes. 

Precisely as the short blocks of bones are arranged in 
the thumb, so they are in the great toe, being, however, 
proportionably larger. There are two in this and three 



34 



ANATOMICAL CLASS BOOK. 



in each of the four remaining toes, — the whole of which 
hXQ phalanges, being fourteen in all. 



Fi-. 24. 



Fi.r. 23. 




Explanation of Fig. 23. 

This represents the bones of 
one toe, as they stand, in relation 
to each other — a the metatarsal 
part, concealed in the muscles, and 
bed the three phalanges. 

Fig. 24 is the skeleton of the 
great toe : a the metatarsal por- 
tion, and b c the phalanges. 



Sesamoid hones, considerably larger than in the thumb, 
are discoverable on the under side of the first joint of the 
large toe. 



SKIN OF THE BONES. — Periostcum. 

Over every bone is a thin, white covering, the perioste- 
um, closely investing it. Its use is to conduct the nutri- 
cious vessels and nerves into the substance of the bone. 
It serves also for the attachment of the muscles, which 
could not otherwise be fastened to the smooth surface. 
Though apparently insensible, it is amply furnished with 
nerves, arteries, and veins, but its vitality is very low. 



ANATOMICAL CLASS BOOK. 35 

GROWTH OF THE BONES ; — or Osteogeny, 

By this term, is understood the doctrine of the formation 

and growth of the bones. From infancy, till the age of 
about twenty years, they are constantly undergoing changes. 
In fact, they are completely renewed, many times in the 
course of a long life. No particle of matter can long re- 
main at rest in a living system. When one portion is re- 
moved, another is put in its place, so that by the circula- 
tion of the blood, the greatest activity prevails, even 
among these earthy portions of the body. 

The arteries, hereafter to be described, are the arti- 
zans, — carrying whatever is necessary to promote the 
growth, or to repair the wastes of the system. They also 
fashion each organ, give shape to every bone, and sustain 
and furnish them with vitality. 

Bones have nerves, but they are small, and only con- 
nect them with the other more highly organized parts. 
When they are diseased, they become painful as the mus- 
cles ; but in health, they are insensible. 

As a whole, the skeleton is merely a frame, on which 
are suspended, or attached, all the organs of motion. It is 
full of joints — and each bone is a lever, to be acted upon 
by the powder of a muscle. This, which in most of the 
large animals is in the centre, in many of the smaller 
tribes, is on the outside, in the form of a shell. Examples 
may be found in the turtle and lobster, beetles, &c. 

Such a remarkable piece of mechanism as the skeleton, 
divested of a thousand important, w^onder-working accom- 
paniments, exhibits in the clearest light, the goodness and 
wisdom of God. The fashion of each bone, and above all, 
the skilful and nice adjustment of the whole, and their 
subserviency to the different fibres and tubes which are 
intimately connected with this complicated, yet perfect 
piece of architecture, must strike a reflecting mind, most 



36 ANATOMICAL CLASS BOOK. 

forcibly, that the evidences of the existence of a Supreme 
Power, are here manifested in a most extraordinary 
manner. 

DIFFERENCES BETWEEN MALE AND FEMALE SKELETONS. 

Were it true that men have a deficient number of ribs, 
there would be no difficulty in designating the skeletons 
of different sexes. To an inexperienced eye, it will al- 
ways be a nice point, to determine one from the other. 

The skeleton of the male is larger and heavier than 
that of the female. The surfaces of the bones are rougher, 
as the muscles which moved them were more strongly de- 
veloped, and capable of exerting more power than those 
of the other. The head of the female, on an average, is 
smaller than the male ; the sutures are less notched ; and 
the cavities in the bone of the forehead, and upper jaw 
bones, are considerably smaller. All the limbs are more 
delicately and slenderly formed. Fiocesses are less prom- 
inent, and depressions are comparatively more superficial. 

A still stronger difference, however, is found in the pel- 
vis, — a kind of arch, or bony circle, bounded by the hip 
bones. In females, the pelvis is much broader than in 
men, and the hips are spread more outwardly. Lastly, the 
necks of the thighbones are longer, — giving them the 
appearance of being particularly broad across the hips : 
thus far, only, females are constructed, in the frames of 
their bodies, to differ very essentially from the male. 
The breadth of the pelvis, in connexion witli the peculi- 
arity of a long neck to the thigli bones, brings tlie knees 
nearer together. 

If two skeletons, one of a man, the other of a woman, 
are suspended, it will be noticed that the lower extreme- 
ties of the male would be nearly parallel to each other; 
whereas, in the other, the knees will approximate so near- 



ANATOMICAL CLASS BOOK. 37 

ly, as to touch. Another difference consists in the capa- 
city of the chest: one is small, and the other is large. 
The bones of the feet and hands are large in men ; — but 
in the female they are slender, smooth and delicate. Fi- 
nally, the height and weight would have an influence up- 
on our judgment in deciding upon the character of either, 

DISTORTIONS TO WHICH THE BONES ARE LIABLE. 

Many injuries of the bones are induced by the careless- 
ness of nurses, in infancy and the first years of childhood, 
which have a permanent influence on the figure and health 
in after life. Females, especially, by the caprice of fash- 
ion, are the subjects of many alarming diseases, arising 
from distortions of the bones. One of the most serious 
affections, a distortion of the spine, is muchoftener found 
in females, than in males. Boys generally lead an active 
li.^e, — enjoying a free exercise of all their limbs, in 
various youthful pastimes. Girls, by a perverse custom, 
are taught that they were made for the house, and not for 
the open air. Their employments are therefore com- 
monly of a sedentary kind, necessarily confining them to 
one posture many hours at a time. Added to this, which 
is enough to enfeeble any constitution, their bodies are 
compressed by the modern modes of dressing, to such a 
degree, that instead of naturally expanding, to give full 
play to the lungs, the chest is kept from enlarging its 
capacity, by stays, and closely fitted dresses. The ribs 
are pressed inwardly, the spine prevented from having 
motion ; the lungs cramped, and consumptions, inflamma- 
tions, and other oftentimes incurable maladies, are the 
certain results. 

Notwithstanding the odium cast upon the Chinese for 
their ridiculous fancy for the small feet of their females, 
which are prevented from growing, by being compressed 
4 



38 ANATOMICAL CLASS BOOK. 

in iron shoes, it is not so cruel nor absurd, as the practice 
among the females of all civilized countries, at the present 
day, of preventing the growth of the waist. 

Physicians, philanthropists and philosophers, have each 
exerted themselves, to awaken an interest, — to arouse 
females to a sense of their danger, but it has been to little 
purpose. Though seriously deformed, they cannot be 
persuaded to abandon a custom, which, in their apprehen- 
sion, improves their otherwise beautiful forms. 

We here introduce the following drawings, to show 
what is the actual condition, of the chest that has become 
permanently diminished by artificial means, compared with 
one that has been developed as nature intended. 

Young ladies require nearly as much exercise as boys, 
but of a less violent character, as their physical organiza- 
tion is not calculated, it is reasonable to suppose, for se- 
vere exertions of the muscles. They certainly require 
loose, easy clothing, that the bones concerned in the forma- 
tion of the apartment in which is placed the vital ap- 
paratus, may be free, unimpeded, and unrestrained. 

^'»- ^^- Co7iti acted chest. 

An outline is here presented of the 
chest of a female, to show the acttial 
condition of the hones, as they appear 
after death, in every lady who has 
h;\hitiially worn stays. 

All the false ribs, fron» the lower end 
of the breast hone, arc unnaturally 
cramped inwardly towards the spine, 
so thnt the liver, stomach and other di- 
gestive organs in the immediate vicini- 
ty, are pressed into such small compass, 
that their functions are interrupted, 
and in fact, all the vessels, hones, and viscera, on which the individ- 
ua! is constantly depending for health, are more or less distorted 
and enfeebled. 

Whatever has a tendency to confine those parts of the 
frame which were designed for motion, positively tends to 




ANATOMICAL CLASS BOOK. 



39 




Fig. 2G. Skeleton of a well formed femah 

chest. 
By comparing the accompanying 
plan ot" a well developed and natur- 
ally proportioned female chest, with 
the frightful skeleton appended to 
the preceding note, the difference 
is strikingly apparent. Here is 
hreadlh, — space for the lung* to act 
in ; and the short ribs are thrown 
outwardly, instead of being curved 
and twisted down towards the spine, 
by which ample space is afforded 
for the free action of all those or- 
gans, which in the other frame, 
were too small to sustain lUe. 
The first inay be regarded as the 
exact shape and figure of a shoi t lived female ; and this may he 
contemplated as an equally true model of the frame of another, who, 
so far as life depends upon a well-formed body, would live to a good 
old age. 

the production of disease ; it is therefore of the highest 
interest to the well being of our species, that an elementa- 
ry knowledge of the structure of the human body should 
be taught, and everywhere understood, — that precautions 
may be taken to avoid a threatening danger. Physical ed- 
ucation is not only too much neglected, but what is still 
more lamentable, scarcely appreciated in this country. If 
parents, in the first place, and instructers in the second, 
studied more the education of the body, the intellectual 
faculties would be more fully, and energetically developed. 
Above all, the young should be instructed correctly, in 
the knowledge of the laws of animal life. 

The lungs too suffer, — and in those cases, which art 
ninety in a hundred, where the stays have been laced on 
in very early life, before the ribs have become perfectly 
ossified, the chest is never developed; — it never assumes 
the form which it would have had, were it not for this 
mechanical restraint ; consequently, for want of capacity, 
or in other words, for the want of room, the lungs are too 



40 ANATOMICAL CLASS BOOK. 

small for the requirements of the body ; — they cannot 
oxygenate the blood, — an indispensable vital process. 

Corset boards are quite as reprehensible, though the in- 
juries to which they give rise, are less apparent in the be- 
ginning. The busk operates almost exclusively on the 
sternum or breast bone, which is easily bent out of its 
original position, at its lower extremity. 

By a constant pressure of an inelastic board, the lower 
end of the sternum, which juts down into the abdominal 
muscles two or three inches, is forced inward, and be- 
coming ossified in that direction, is productive of serious 
injury to the stomach, which lies just behmd it. 

A multitude of painful and protracted diseases, by 
which females in the higher walks of society, in this age, 
are hurried to an early grave, have their origin in this hor- 
rible custom of wearing stays. Thousands upon thou- 
sands of young ladies are the yearly victims, even in the 
United States, to consumption^ which is wholly referable 
to this fashionable, but perverted taste, of conforming to 
a practice which has for its object, the improvement of 
the female form ; as though the Creator, in constructing 
the most beautiful work of his creation, neglected to give 
that last finishing process, which they imagine them- 
selves to have discovered, and which can alone be satisfac- 
tory to the sex. 

While we lament the tolerance of an evil in our coun- 
try that sweeps the young, the beautiful, and the intelligent 
to the tomb, before the summer of life has fairly commenc- 
ed, we scarcely indulge the hope of a reformation: per- 
nicious customs which are preserved by common consent, 
Cannot be easily overcome by persuasion or argument. 

If, notwithstanding the many illustrations given of the 
sad effects of stays and busks, by various philanthropic 
writers, mothers and nurses manifest no disposition to be 



ANATOMICAL CLASS BOOK. 41 

influenced by their opinions and advice, the duty most 
certainly devolves on all public teachers, in a delicate and 
appropriate manner, to instruct their pupils in the first 
principles of preserving healthy by explaining the morbid 
effects which arise from confining the body in stays. 

One of the first lessons in physical education should be, 
to strip from the pupil every unnecessary artificial restraint 
upon the body and limbs, 

TEETH. 

In manhood, there are thirty-two teeth, divided in the 
following manner : 

8 Incisores, — or cutting teeth. 

4 Cuspidati, — or dog shaped, — being pointed. 

8 Bicuspides, — or two pointed double teeth. 

8 Molares, — or giinding teeth. 

4 Dentes Sapientiae, — or wisdom teeth. 

The first set, or milk teeth, are twenty in number, ap- 
pearing from time to time, from the age of about ten 
months, to three years, when they are all developed. 
There are, however, many variations as respects the peri- 
od of cutting them, depending on constitutional causes. 
When the roots are absorbed, the tops fall off from the 
gums, and the second set are protruded. The jaws, in the 
mean time, become longer and broader, which allows room 
for an increased number, of a greater size. 

In the centre of each tooth, is a cavity, in which the pulp 
3f a nerve lies, and which is the seat of pain, when the 
oody of the tooth is so decayed as to expose it to the air, 
or bring it in contact with food. Each root is also hollow, 
allowing the fibre of a nerve to communicate with the 
nerves of the jaw, and blood vessels also run in by the 
^ide of it, to nourish the whole. 

The enamel is the outside, hard crust, which gives the 
requisite finish to the tooth, and renders it strong enough 
4* 



42 ANATOMICAL CLASS BOOK. 

for mastication. This enamel is much thinner on the teeth 
of some persons than on others, and scaling off, the bony 
part of the teeth being exposed, soon falls into disease by 
the contact and influence of various kinds of food, drink, 
heat and colds. 

Acids of all kinds are particularly injurious to the teeth, 
because they act chemically on the lime contained in the 
enamel, — destroying the connexion of the particles, and 
thus, ultimately, exposing the nerve. Hot drinks are 
also pernicious. 

Individuals living on moderately cool food, and drinking 
cold water, simply, preserve their teeth in all their origi- 
nal beauty and goodness, to an advanced period. 

Sugar is not destructive to the teeth, as generally sup- 
posed : slaves, on sugar plantations, possess the finest sets, 
uninjured, apparently to extreme old age. 

Cold water only is advisable, applied with a soft brush, 
for keeping them white, clean and in a healthful condition. 
The various dentifrices, salt, ashes, charcoal, (S^c, actually 
injure them by attrition in the application, and should 
never, therefore, be used. Chewing and smoking tobacco, 
is very destructive to the teeth. To youth these few prac- 
tical considerations are worth their recollection. 

When the teeth are all extracted, the sockets which sup- 
ported them are absorbed, and hence the jaws are nar- 
rower, which explains the reason why, in old age, the 
mouth is smaller and the lips sunken : it also accounts 
for the difficulty with which words are articulated. The 
tongue being compressed, moves with less freedom, and 
distinct enunciation becomes extremely difficult. 



ANATOBIICAL CLASS BOOK. 43 



aUESTIONS. 



What is understood by Anatomy ? 
What is Comparative Anatomy and its use ? 
Into how many parts is the science divided ? 
What is Osteology ? 
What is Syndesmology ? 
What is Myology ? 
What is Bursology ? 
What is Angiology? 
What is Adenology ? 
What is Splanchnology ? 
What is Hygrology ? 
How are the bones classed ? 
How are the names of bones derived? 
Are they hollow or solid ? 
What are processes and their use ? 
What is a natural skeleton ? 
What is an artificial skeleton ? 
How many bones compose the skeleton ? 
How is the skeleton divided by anatomists ? 
How many bones compose the skull ? 
How many are there in the face ? 
How many teeth and how arranged ? 
Has the tongue any bone ? 
Is the sense of hearing dependent upon bones? 
How many bones compose the trunk ? 
What are Sutures? 
Where is the Coronal Suture ? 

How does the male differ essentially from the female skele- 
ton ? 



44 ANATOMICAL CLASS BOOK. 

Why are some bones hollow ? 

What is the use of marrow ? 

How many bones in the fore arm ? 

How many in the wrist ? 

What is the carpus ? 

Where is the metacarpus ? 

How many phalanges in the fingers ? 

How many bones in the foot ? 

Are extra bones ever found — and if so, where ? 

How are bones said to be united ? 

Where is the os frontis ? 

Of what use are the cavities in the bones of the forehead 
and cheeks ? 

Where is the occipital bone situated ? 

What circumstance renders the temporal bone particu- 
larly interesting ? 

What do you understand by the spine ? 

Why are persons taller in the morning than at night? 

Why are aged persons inclined to be crooked, and ehorter 
than in their youth ? 

How many ribs are there ? 

What is meant by pronation of the hand ? 

What by supination ? 

What is the use of the periosteum? 

What is osteogeny ? 

Have bones any sensibility ? 

How do they grow, or how are they repaired when injured? 

What is the use of the skeleton ? 

What is the metatarsus ? 

What are ligaments ? 

How many bones in the arm ? 

How many teeth in adults ? 

Where is the sternum ? 

What is the use of the clavicle? 

How many bones in the foot ? 

Of what use is a bone in the tongue ? 

Are there more ribs in a male than in a female skeleton ? 



ANATOMICAL CLASS BOOK 45 



LIGAMENTS. 



OR SYNDESMOLOGY, 



In the economy of the system, the skeleton would have 
been in a very imperfect condition, if so many bones were 
not firmly connected together. The bands and straps 
which so effectually and strongly connect them, one with 
another, are called ligaments, and syndesmology is the 
study or doctrine of them. 

Such is the prodigious tenacity of the ligaments, that 
the bones are sometimes fractured, before they are torn 
from their points of adhesion. 

Ligaments, like the bones themselves, are nearly insen- 
sible, white and shining, and commonly short, thin and 
tough. Where the ends of two bones meet, as in the con- 
struction of a joint, their situation is maintained by liga- 
ments running from one to the other. Possessing but a 
very slight degree of elasticity, the joints do not become 
loose or shackling, unless extension is maintained a very 
long time. 

Were it not for ligaments, the bones of our bodies would 
fall down by their own weight. A natural skeleton is 
one on which they have been preserved, with reference to 
showing the precise connexion of the bones. 

Some ligaments are exceedingly interesting, from the 



46 



ANATOMICAL CLASS BOOK. 



Fig. 27. 




Explanation of Fig, 27. 
e, d, are the crucials or cross liga- 
ments, so remarkable in structure and 
office ; /, the tendon of an extensor 
muscle; c, the head of the fibula, 
joining the side of the shin bone; a, 
the articulating surface of the lower 
end of the thigh bone, covered by the 
knee pan ; 6, refers to the broad liga- 
ment, turned down from the joint to 
expose the cross ligaments, having 
the knee pan on it. 



circumstance that they keep a joint frpm bending the 
wrong way. The knee would be the weakest, and most 
liable to get out of order, of any, were it not for its nume- 
rous ligaments. 

Within this joint, two ligaments are so arranged, that 
they cross each other, like the legs of a saw-horse, com- 
pletely preventing the leg from being carried too far back- 
ward or forward. The lateral ligaments guard against dis- 
locations on either side. 

One single round ligament fastened on the head of the 
thigh bone, ties it into the centre of its socket, keeping it 
always in place, however much the limb be moved in 
opposite directions. 

Ligaments exist wherever two bones meet at their ex- 
tremities, and also abound in the cavities of the body, 
in the form of flat or round cords, to sustain the weight 
of important organs, as the liver, spleen, and pancreas. 
Without these supports the liver would inevitably fall 
down, from its place just under and behind the false ribs 
of the right side, upon the hollow organs below. The 



ANATOMICAL CLASS BOOK. 



47 




Explanation of Fig. 28. 
Complex as the ligaments appear 
in this plan, there is certainly an 
admii'able simplicity, conducing ex- 
actly to the perfection of the frame 
of the hand. Each letter, as in 
other dias^rams, shows the place of 
each individual ligament, as found 
on dissection, joined to the bones, 
which are thus drawn together like 
so many wedges. It would be 
utterly impos.-ible for the most in- 
genious mechanic to take the dry 
bones and secure them together by 
vires, clasps, rivets or straps, so 
strongly as nature has done by means 
of these little shining ligaments. 



gall-bladder is lied to the liver by a ligament ,• the intes- 
tines are kept in their places by ligaments ; — the stomach, 
too, without ligaments would soon be thrown by its own 
muscular exertions, during digestion, from its natural lo- 
cality. Even in the skull, ligaments assuming various 
forms, support the lobes of the brain, protect vessels, and 
give strength to the architecture of the head during the 
first years of life. Indeed, ligaments are indispensable 
throughout the animal frame. 

By means of them, the small bones of the foot are kept 
firmly together in the shape of an arch, in the instep : — 
otherwise the weight of the body, in the exercise of walk- 
ing, would crush them apart, and forever destroy their 
curious connexion. 



48 



ANATOMICAL CLASS BOOK. 



Fig. 29. 




Explanation of Fig. 29. 

By this drawing, which is true to 
nature, it will be seen, distinctly, how 
the bones of the instep and ankle, are 
articulated ; — how the instep and pha- 
langes or toe bones meet; and lastly, 
the small letters direct the eye to the 
locality of each ligament, which assists 
in binding this congeries of large and 
small blocks firmly together, like a 
pavement. 

In cases of club-foot, the ligaments 
are very much deranged, in conse- 
quence of the distortion and displace- 
mtfnt of the bones. But, however for- 
midable the case may appear, if season- 
able exertion is made, the very worst 
club-foot may be re-modelled by an iron 
shoe, provided wiih metallic rods run- 
ning up by the sides of the ankle, so 
that both the apparatus and bones may 
he kept in place. Without the advice 
of a surgeon, any ingenious mechanic 
can remedy a malformation of the toot, 
if the trial is commenced while th» 
bones are imperfectly ossified. 



By ligaments the wrist is fastened to the arm, indepen- 
pendently of muscles; the shoulder to the shoulder blade; — 
the head to the first bone of the neck ; — the ribs to the 
spine, and the vertebrae to each other. The office, there- 
fore, which these deep seated, almost unnoticed straps 
hold, in binding the whole frame together, cannot be 
overlooked by any one who contemplates the marvellous 
work of God, as exhibited in our own complex, yet beau- 
tifully fashioned bodies. 



ANATOMrCAT. CLASS BOOK. 

Fig, 30, 



49 




Explanation of Fig, 30. 
Having completed a general description of all the individual bones, 
and exhibited some of the principal lig'amentsof the limbs, the object 
of this third drawing; of an entire skeleton, is first, to give aside view 
of the parts adverted to in the foregoing pages, — without letters or 
references to deface the engraving, or to perplex the mind. The 
peculiar attitude of the figure was given it by the artist, merely be- 
cause a larger sized drawing could thus be given in a little space. 



50 ANATOMICAL CLASS BOOK. 



THE MUSCLES. 

OR MYOLOGY. 

An interesting department of anatomy is called myology^ 
or the doctrine of the muscles. 

We would by no means surfeit our young readers with 
the consideration of subjects which are only considered 
valuable to the anatomist : — but we wish general inquirers 
to participate in some of those sublime manifestations of the 
all-creative Power, presented in the mechanism of animal 
bodies, which have too long been locked up in libraries. 

All that pertains to anatomy, either human or compara- 
tive, possesses the highest degree of interest. 

We are not so enthusiastic as to suppose that every 
body can be induced to feel so earnestly devoted to this 
science as ourselves ; — nor is the desire entertained of 
making dry bones a fashionable topic of general conversa- 
tion ; but we do most fervently hope that the leading 
principles of anatomical and physiological knowledge 
will be diffused ; will yet be taught in all the schools of 
this country. 

The advantages to youth, arising from a public dissemi- 
nation of these sciences, will be very numerous, as it will 
lead the young to correct views : — it will dispel that 
vulgar kind of mystery in which the functions of individual 
organs are enveloped : — it will strengthen the morals, 
elevate the mind, and finally, be one of the surest means 
of fixing the attention to the considerations of the char- 
acter and Omnipotence of God. 



ANATOMICAL CLASS BOOK. 51 

Ordinarily, there is more vulgar curiosity, seeking to 
be gratified on a variety of topics, embraced in these 
vaiuable sciences, than in almost any other. Next to 
the insane expectation of converting the base metals into 
gold ; — the desire and the hope to prolong the period of 
life, to raise the dead, and to avert disease, has always 
been founded on a limited and false knowledge of anato- 
my. Those who are truly learned in the science, dis- 
cover the impossibility of maintaining never failing youth : 
they are convinced of the necessity of death, the only 
means of allowing a succession of beings ; — the only 
means by which matter can assume the forms that insure 
this unfailing result. 

Our bodies are indeed marvellously constructed ; the 
materials of which they are composed, possess the most 
opposite characters, — and the effects produced by the 
harmonious operation of each fibre, however minute 
or remote, contributes somethmg towards the perfec- 
tion of the whole. The moving powers, the self-acting 
levers, and the invisible something which guides the 
movement, or limits the duration of action, belong to 
another inquiry ; yet, before arriving there, it is first 
necessary to investigate the instruments of motion, the 
muscles. 

MUSCLES. 

There are 527 muscles in man, 257 being in pairs. 

Wherever there is a joint to be flexed, a bone to be 
moved, or a motion of any kind to be effected, it is entirely 
executed by muscles. Muscles are, in popular language, 
Jlesh; but instead of being an irregular mass, as too com- 
monly supposed, exact order is maintained ; a certain 
number of threads are invariably deposited, with syste- 
matic attachments, with reference to a specific kind of 
motion. 



52 ANATOMICAL CLASS BOOK. 

Chance has nothing to do with the muscular tissues. 
Each muscle is formed by an exact rule, from which 
nature never departs, without exhibiting a monster, 
whose motions are so far a deviation from the species, that 
the individual is physically defective, and incapable of 
transmiting it to its offspring. A majority of the cases in 
which too many or too few organs are seen, are to be im- 
puted to incidental causes, which prevented nature from 
completing those portions, the absence or excess of 
which constitutes the essential characteristics of a species. 
The laws of the animal economy are immutable. 

The figures of the muscles are as various as possible, 
some being round, others square, triangular, or flat like a 
ribbon. In length too, the variations are remarkable. 
Belonging to the vocal box, the {larynx^) the muscles, 
opening and closing the rima glotid/'s^ to vary the strength 
of voice, are only about an eighth of an inch : the sar- 
iorius, or tailor's muscle, by which the legs are crossed, 
arises on the top of the hip bone, and extends six inches 
below the knee, passing two joints, — being nearly three 
feet long. On the back, the laiissimus dor si ^ by which 
the hand is brought downward and backward, as by a 
blacksmith in using a hammer, is a foot broad on the 
back, scarcely an inch in width at its attachment to 
the arm, below the shoulder, but all of two feet in 
length. 

All muscles, are large in the middle, but small at the 
extremities : — each one, too, is enveloped in a sheath, to 
keep it separate from a contiguous one, that the action 
may not interfere with the assigned office of any other. 
Indeed, each bundle of fibres of which the muscle is com- 
posed, is secured in a sheath of its own, and the whole 
are finally encased in the outside tissue, that binds down 
and secures the whole. 

These coverings of the muscles are elastic, stretching 



AJ^ ATOMIC AL CLASS BOOK. 53 

and recovering their original form when the contents arc 
relaxed. When the greatest degree of contraction takes 
place, as in the muscles of the thigh, the power of the 
muscle is increased a hundred fold by the tightness of 
the fascia. On the arm, for example, between the elbow 
and shoulder, the flexor of the fore arm, in a state of 
action, produces a very prominent ball near the middle 
of the bone: on the inferior extremities, were the muscles 
to project out in such a manner, all symmetry would inevi- 
tably be sacrificed, and the power too, would be very 
much abridged. Laborers bind a cord round the arm 
when they wish to exert an extraordinary degree of 
strength : — sailors, too, in order to increase their muscu- 
lar power, usually wear a tightly girded leather belt just 
above the hips, — the principle of which is to bind down 
the bellies of the muscles, more closely than the straps 
which nature has placed over them. 

The muscles are divided into two classes, viz : the vol- 
untary, and involuntary ; the first are subservient to the 
will ; but the second order is wholly beyond its influence. 
To put the voluntary muscles in action, we have only to 
will it; to incline the power to effect an orderly contrac- 
tion. It is only necessary to will the bending of a finger, 
and it is done — to will the clenching of the hand, and 
the action follows instantly ; to flex the leg, or extend the 
foot, and the command of the brain is obeyed. 

On the other hand, the muscular fibres of the stomach 
are independent of the mind : the ear receives sonorous 
rays, and propagates them to the labyrinth, by the com- 
bined muscular apparatus within, nor can we prevent it 
by any effort of the mind to the contrary. 

Before muscles become orderly — before they can serve 
the mind, they must be taught. Thus the child is obliged 

5* 



54 ANATOMICAL CLASS BOOK 

to totter round the room, receiving severe falls, before the 
muscles become trained to the business for which they 
were designed. The infant that has crept, feels safer on 
its hands and knees, than on its feet, because, by prac- 
tice, the locomotive muscles obey the child in that posi- 
tion, and it is conscious of its security, from its recollection 
of the fact. 

When the child first endeavors to maintain an erect 
posture, its step is insecure, the muscles not having 
been associated to act in the new trial ; the positive influ- 
ence of mind, therefore, must not be suspended an in- 
stant ; if it is, the infant falls to the floor. 

When, therefore, any number of muscles have had 
practice in any particular mode or time, a habit is ulti- 
mately established, enabling them to continue the accus- 
tomed motion, without the watchful efforts of the mind. 
It is in this way that we learn to walk, to articulate words, 
to rise, to sit, or assume a daily multitude of positions. 

The principal difficulty the young musician has to en- 
counter in learning to play an instrument, consists in 
teaching the muscles of the fingers to move as rapidly as 
the notes are presented by the brain. Hence the long 
practice required, before rapid execution is attained. By a 
long course of schooling, the player can at length partially 
withdraw the mental superintendence, — he can slumber, 
or abstract his thoughts from the air, or enter into conver- 
sation, but the fingers continue their unerring course, in 
time and with surprising accuracy. 

The most opposite, and apparently incongruous associ- 
ations of muscular action, are exhibited by rope-dancers, 
in throwing carving-knives, which fall in a perfect line, 
points downward, toward the crown of the head, while 
heavy brass rings are whirled with extreme rapidity in op^ 
posite directions, on each of the gre^i toes. Such exam- 
ples of the extraordinary feats that may be accomplished 



ANATOMICAL CLASS BOOK. 55 

by teaching muscles to act differently from what they ap- 
pear to have been expressly intended, are exceedingly 
common, but not the less surprising. 

It must not be lost sight of that the two orders of mus- 
cles are obedient to their proper rulers ; the one being 
under the express dominion of the mind, and the other 
influenced only by its appropriate stimulus. Food is the 
natural excitant of the muscular tissue of the stomach, 
and the blood, by its presence, stimulates the fibres of the 
heart. 

Bat the most perplexing circumstance in relation to 
the muscles, is the property of contraction. Every mus- 
cle in the body is always tense ; relaxation is a misapplied 
expression, if it were understood that the rest of the 
muscle is like a rope slacked till it becomes pendulous 
between two points of attachment. However much a 
joint may be bent, the muscles always remain tense ; ap- 
parently as much so, as when actually put upon the stretch 
by the extension of the same joint. They carry their 
contraction still further in cases of luxations. 

When the hip joint is dislocated, the muscles of the 
thigh, finding nothing to oppose them, shorten the limb by 
inches, and hold their grasp so tenaciously that pulleys are 
required to overcome their unrestrained, unauthorized 
activity. 

When the joint has been too long neglected, and the 
head of the bone cannot be carried back to the socket, on 
account of the violent rigidity of the surrounding muscles, 
they invariably continue in that condition through life. 
Such a limb is consequently thicker than its fellow, the 
circumference being gained at the expense of its length. 

Muscles are never ID ear y — no, never, under any cir- 
cumstances whatever ; if that were possible, there would 
be examples of their inability to answer the requirements 
of the will, from this cause. The mind's control over 



66 ANATOMICAL CLASS BOOK. 

them may be suspended or even lost, as will be shown 
directly, but still they are always active, and always in a 
state of contraction. If their irritability were reduced 
by fatigue, it could not be recalled ; the vis insita, the 
life of the muscle, survives the departure of the soul, and 
keeps it in a moderate contraction long after the vital tem- 
perature has been lost. 

Nothing, indeed, short of putrefaction, destroys its con- 
tractility. Death, by which is meant the separation of the 
spiritual essence from the material body, does not destroy, 
suddenly, the life of the flesh, as that survives for days and 
even weeks. The truth of this position is established by 
the application of galvanism to the bodies of malefactors 
— the rolling eye-balls, the cramped limbs, the heaving 
chest, and in the fiendish expression of the muscles of 
the face. 

An illustration of the permanency of this irritability 
may be seen also in the quivering meat hung up in the 
shambles of the market ; it is exhibited in the writhings 
of the eel deprived of its head and its skin ; and in the 
violent snapping of the tortoise's jaws, many days after 
decapitation. 

When we are perfectly exhausted, by reason of long 
continued fatigue, the muscles are not the sufferers ; they 
then show their activity by violent exertions. Cramps, 
severe paroxysms, and painful contractions, at such times 
supervene, and rarely at any other. These arise from the 
loss of the nervous powers which is the regulator of the 
system. 

That power may be diminished by long continued ex- 
ercise, by extreme watchfulness, or by many other causes. 
Yet while it is feeble, the muscles twitch, and permanent 
distortions ensue, if the nerves do not recover their ener- 
gy. We retire to our beds, not to give the muscles an 
opportunity of reposing, but to recover nervous influence. 



ANATOMICAL CLASS BOOK. 57 

Every muscle has an antagonist, with a few exceptions. 
Where there is one to draw in one direction, there is an 
opponent to counteract ; by this contrivance, a complete 
freedom of motion is given to the extremities. Each 
flexor has, opposed to it, an ex<;ensor ; and the contraction 
of one, is partially accomplished by the relaxation of the 
other ; but the simultaneous action of both, fixes the part 
on which they exert their power ; thus, the flexors on the 
fore part of the neck, and their antagonists on the 
back side, maintain the head in a vertical line with the 
body. 

Each muscle terminates in a hard, white cord, appa- 
rently the compressed threads constituting its volume, al- 
though such is not the fact. These are called tendons^ 

At the place of origin, the tendon is thin, inelastic, and 
short, soon intermingling itself with the substance of the 
muscle ; but at the other end it assumes another form, 
being either round, or delicately smooth, tape-like and 
narrow. This is the part which passes over a joint to be^ 
come attached to the next bone. Tendons are nearly in- 
sensible, being so far removed from the ordinary sensibil- 
ity of everything else, that they rarely participate in the 
diseases to which all the soft portions of the frame ar^ 
subject. 

To obviate friction, and prevent interference with its 
neighbors, each tendon is invariably conducted through a 
sheath, in which there is a copious secretion of a fluid, 
resembling oil, that keeps the cord soft, that it may glidje 
easily. 

Symmetry of form is wholly referable to the tendons. 
Without them, the exceeding bulk of the muscle would 
produce, according to our present notion of the beautiful, 
the most hideous deformities. 

Were the muscles of the fore arm carried to the palm, 
of the same size that they have at the elbow, the wrist 



5S ANATOMICAL CLASS BOOK. 

would be the diameter of the elbow — rendering the hand 
unwieldy and nearly useless. 

To the free circulation of the blood into its inmost re- 
cesses, the muscle is indebted for its vigor; and to the 
nerves, for that sensitiveness which renders it susceptible 
of painful or pleasurable sensations. 

In its constitution, however, the muscle possesses a 
sensibility, completely beyond the control of any nerves in 
the body ; a curious circumstance indeed, referred to in 
speaking of its vis insita. An exhibition of this proper- 
ty — this disposition to recoil under excitement; to remove 
itself from the contact of foreign substances ; in short, to 
preserve itself from the destructive agency of whatever 
has a tendency to exhaust its latent irritability, is within 
common reach. A demonstration of this phenomenon 
may be witnessed in the hearts of reptiles, pulsating by 
the prick of a pin, long after being removed from the ani- 
mal ; in the motion of the intestines of cats and dogs, cut 
into strips. While the vital temperature remains, they 
move like earth-worms, and when they have ceased to 
move, their irritability can be roused again by the applica- 
tion of stimuli. 

Here, then, is exemplified the existence of a property, 
purely vital, which never was, and in the instance before 
us, could not be influenced by the nervous system. 

Removed as this property is, from the direct influence 
of the nerves, it becomes, under peculiar circumstances, 
the only hope. In cases of suspended animation, as in 
drowning, swooning, &;C, there is a prostration of the 
nervous system — it cannot act — the will cannot produce 
an impression on the muscles, because its messengers, the 
nerves, are no longer in a condition, from some unknown 
cause, to transmit the orders. At this juncture, if no 
saving efforts are made, the individual dies. But a skil' 



ANATOMICAL CLASS BOOK. 59 

fill application of agents to the muscles, raises their tone 
to that high degree of excitability, that they actually re- 
suscitate the expiring spirit of the nerves. The instant 
that is effected, the sign of success is manifested by 
the obedience of the muscles ; the poor sufferer moves a 
limb, because he determines it ; order is at the same in- 
stant restored in the nerves, and the sufferer is restored 
to life, and his weeping friends to happiness. 



A CATALOGUE OF THE PRINCIPAL MUSCLES. 

Perhaps it may be thought tliat the following table is 
not only unnecessarily minute, but altogether too techni- 
cal ; but as we could devise no method of rendering it 
much more simple, without making the whole unintelligi- 
ble, — the scientific names of the points of origin and in- 
sertion^ have been preserved. It is not expected that 
children will either be interested or required to learn this 
intricate division of anatomy, even should the first prin- 
ciples of the science be generally taught in common 
schools. 

For instructers, however, drawing-school pupils and 
young artists, the few technical words which are retained, 
will be of consequence, as they will be able to refer to the 
skeleton, (\vhich we also hope will be considered, at no 
very remote period, an indispensable part of school appa- 
ratus,) for the exact places to which they refer. 



Note. — Where the muscle has no fellow, it is marked 
thus. "^ It should be recollected that the muscles of one side 
of the body only, are here considered. 



60 



ANATOMICAL CLASS BOOK. 



MUSCLES OF THE HEAD, EYELIDS, EYEBALL, NOSE AND MOUTH. 



Occipito-frontalis.* 



Corrugator supercilii. 

Orbicularis palpebrarum. 

Levator palpebree superi- 
or is. 

Rectus superior. 
Rectus inferior. 
Rectus internus. 
Rectus externus. 
Obliquus superior, or Tro- 
chlearis. 



Obliquus inferior. 



Fig 31. 




jJrises from 

The upper ridge of the oc- 
cipital bone; its aponeurosis 
covers the upper part of the 
head. 

Above the root of the nose. 

Around the edge of the 
orbit. 

The bottom of the orbit 
near the optic foramen. 

Around the optic foramen 
of the sphasnoid bone, at the 
bottom of the orbit. 

Near the optic foramen, and 
passes through a loop in the 
internal canthus of the eye, 
and is reflected to be 

The ductus nasalis, and is 
inserted 



Explanation of Fig. 
31. 

a, the pyramidalis 
nasi; o, the com- 
pressor nasi ; a, oc- 
cipito frontalis; c, 
orbicularis palpe- 
brarum; p, corruga- 
tor supercilii ; n, le- 
vator paJpebrce supe- 
rioris ; f, zygomati- 
cus major ; e, zygo- 
maticus minor ; i, 
orbicularis oris ; A", 
depressor anguli or- 
is ; 777 , depressor la- 
bit inferioris ; h, the 
masseter muscle ; gy 
the buccinator; 5, 
levator labii superio- 
sis alceque nasi ; g, 
the parietal bone 
seen beyond the cor- 
onal suture. 



ANATOMICAL CLASS BOOK. 



61 



MOSCLES OF THE HEAD, EYELIDS, EYEBALL, NOSE AND MOUTH. 



Inserted into 
The skin of the eyebrows 
and root of the nose. 



The inner part of the occi- 
pito-frontalis. 

The inner corner of the 
eyes. 

The cartilage of the tarsus 
of the upper eyelid. 

The anterior part of the 
tunica sclerotica, opposite to 
each other. 

The posterior part of the 
bulb, between the rectus and 
the entrance of the optic nerve. 

Opposite to the former. 



Use. 

To pull the skin of the head 
backward — raise the eye- 
brows and skin of the fore- 
head. 

To wrinkle the eyebrows. 

To shut the eye. 

To open the eye, by raising 
the upper eyelid. 

To raise it upward. 

To pull it downward. 

To turn it to the nose. 

To move it outward. 

To roll the eye, and turn 
the pupil downward and out- 
ward. 

To roll the eye. 



By recurrino; to the plate, (Fig. 31,) the pupil will form a tolera 
bly accurate idea of the muscles of the face. They lie vevy super- 
ficially, just under the skin, and are all muscles of expression ; 
therefore only perfectly developed in the European, or white man's 
face, in whose countenance the passions of the mind are stron2:ly 
exhibited. In the ne2:ro, owinj^ partly to the color of the skin, the 
expression is necessarily very imperfect: — he can never have maj- 
esty nor dignity, or an elevation of thought, portrayed in his fea- 
tures. When the jet black negro expresses his emotions, — unless 
the teeth, and the whites of the eyes are exposed, — there is little va- 
riety of expression, because no shades are created by the contrac- 
tions of the muscles. This fact is familiar to artists, — to the en- 
graver and the painter. The pictures of colored persons are always 
very nearly alike ; the portrait of one, indeed, will answer for 
many, — and the circumstance is wholly referable to the imperfect 
manner in which the light and shadows are created on the skin. 

The muscles of expression are fewer and smaller, as animals de- 
scend the scale of creation. 



62 



ANATOMICAL CLASS BOOK. 



JVame. 

Levator labii superioris 
alaeque nasi. 

Levator labii superioris pro- 
priiis. 

Levator anguli oris. 

Zygomaticus major. 



Zygomaticus minor. 
Buceinator. 

Depressor angnli oris. 
Depressor labii inferioris. 



Jirises from 

The nasal process of the 
superior maxillary bone. 

The upper jaw, under the 
orbit. 

The orbitar foramen of the 
sup. max. bone. 

The OS jugale, near the 
zygomatic suture, and runs 
downward. 

Above the zygomaticus ma- 
jor. 

The sockets of the last mo- 
lares, and the coronoid pro- 
cess of the lower jaw. 

The lower edge of the un- 
der jaw, near the chin. 

The inferior part of the 
lower jaw, next the chin. 




ANATOMICAL CLASS BOOK. 



63 



Inserted into 
The upper lip and ala of 
the nose. 

The middle of the upper 

lip. 

The orbicularis, at the an- 
gle of the tiiouth. 

The angle of the mouth, 
with the depressor of the lip. 

The angle of the mouth. 

The angle of the mouth, 
and is perforated by the duct 
of the parotid gland. 

The angle of the mouth. 

The middle of the under lip. 



Use, 

It raises the upper lip, and 
dilates the nostrils. 

To pull the upper lip di- 
rectly upward. 

To raise the corner of the 
mouth. 

To inflate the cheek and 
raise the angle of the mouth. 

To raise the angle of the 
mouth outward. 

To contract the mouth, and 
draw the angle of it outward 
and backward. 

To draw the corner of the 
mouth downward. 

To draw the under lip down- 
wardand outward. 



d. 
e. 
/. 

g- 
h. 
i. 

i 

I, 
m. 
n. 
o. 

P- 
2. 
3. 

4. 

5. 



Explanation of Fig. 32. 
The occipito-frontaiis. 
The orbicularis palpebrarum. 
The corrugator supercilii. 
The compressor naris. 
The orbicularis oris. 

The levator labii superioris alaeque nasi. 
The levator anguli oris. 
The zygoiiialicus major and minor. 
The depressor anguli oris. 
The depressor labii inferioris. 
The buccinator. 
The masseter. 

The temporal fascia, or aponeurosis. 

The parotid gland, which supplies the raouth with saliva. 
Steno's duct, to conduct the fluid into the mouth. 
The temporal artery. 
The facial artery. 

Parts seen in the neck. 
The sterno-cleido mastoideus. 
The omo-hyoideus. 
The sterno-hyoideus. 
The steriio-thyroideus. 
The digastricus. 
Ths stylo-hyoideus. 
. The mylo-hyoideus. 

The submasillary gland — also pours saliva into the mouth. 
The external jugular vein. 
The sheath containing the carotid artery. 



64 



ANATOMICAL CLASS BOOK. 



Orbicularis oris.* 



Depressor labii superioris 
alaeque nasi. 

Constrictor nasi. 

Levator menti vel labii in- 
ferioris. 



Arises from 

This muscle surrounds the 
lips, and is in a great measure 
formed by the buccinator, zy- 
gomatic!, and others, which 
move the lip. 

The sockets of the upper 
incisor teeth. 

The root of one wing of the 
nose, and 

The lower jaw, at the root 
of the incisors. 



MUSCLES OF THE EXTERNAL EAR. 



Superior auris, or attollens 
aurem. 
Anterior auris. 

Posterior auris, or retrahens 
auris. 

Helicis major. 

Helicis minor. 

Tragicus. 

Antitragus. 
Transversus auris. 



The tendon of the occipito- 
frontalis above the ear. 

Near the back part of the 
zygoma. 

The mastoid process, by 
two and sometimes three fas- 
ciculi. 

The upper, anterior, and 
acute part of the helix. 

The interior and anterior 
part of the helix. 

The outer and middle part 
of the concha, near the tragus. 

From the root of the inner 
part of the helix. 

The upper part of the con- 
cha. 



MUSCLES OF THE INTERNAL EaR 

Laxator tympani. 



Tensor tympani. 
Stapedius. 



The spinous process of the 
sphaenoid bone. 

The cartilaginous extremity 
of the Eustachian tube. 

A little cavern in the pe« 
trous portion, near the cells 
of the mastoid process. 



ANATOMICAL CLASS BOOK. 65 

Inserted into Use. 

To shut the mouth, by con- 
tracting the lips. 



The root of the ala nasi and To pull the ala nasi and 
upper lip. upper lip down, 

goes across to the other. To compress the wings of 

the nose. 

The skin in the centre of To raise the under lip and 
the chin. skin of the chin. 



RIUSCLES OF THE EXTERNAL EAR. 

The root of the cartilagi- To draw the ear upward, 

nous tube of the ear. and make it tense. 

The eminence behind the To raise this eminence for- 

helix. ward. 

The septum that divides the To draw the ear back, and 

ecapha and concha. stretch the concha. 

The cartilage of the helix, To depress the upper part 
a little above the tragus. of the helix. 

The crus of the helix. To contract the fissure. 

The upper part of the tra- To depress the concha, and 
gus. pull the tragus a little out- 

ward. 
The upper part of the anti- To dilate the mouth of the 
tragus. concha. 

The inner part of the helix. To draw these parts toward 

each other. 



MUSCLES OF THE INTERNAL EAR. 

The long process of the To draw the malleus ob- 
malleus. liquely forward, toward its 

origin. 
The handle of the malleus. To pull the malleus and 

membrane of the tympanum 
toward the petrous portion. 
The posterior part of the To draw the stapes oblique- 
head of the stapes. ly upward toward the cavern. 
6* 



66 



ANATOMICAL CLASS BOOK, 



MUSCLES OF THE LOWER JAW. 



JVame, 
Temporalis. 



Masseter. 

Pterygoideus internus. 
Pterygoideiis externus. 



Arises from 

The lower part of the pari- 
etal bone and os frontis ; 
squamous part of the tempo- 
ral bone ; back part of the os 
jug-ale ; the temporal process 
of the sphsenoid bone, and the 
aponeurosis which covers it. 

The sup. max. bone, near 
the OS jugale ; and from the 
anterior part of the zygoma. 

The internal pterygoid pro- 
cess of the sphsenoid bone. 

The external pterygoid pro- 
cess. 



MUSCLES ABOUT THE NECK. 



Platysma myoides. 
Sterno-cleido-mastoideus. 



The cellular membrane cov- 
ering the pectoral and deltoid 
muscles. 

The upper part of the ster- 
num, and fore part of the clav- 
icle. 



Fig. 33. 




ANATOMICAL CLASS BOOK. 67 

MUSCLES OF THE LOWER JAW. 

Inserted into Use, 

The coronoid process of the To move the lower jaw up- 
lower jaw, its fibres being ward, 
bundled together and pressed 
into a small compass, so as to 
pass under the jngum, or zyg- 
oma. 

The angle of the lower jaw To raise and move the jaw 

upwards to the basis of the a little forward and back- 

coronoid process. ward. 

The lower jaw on its inner To raise the lower jaw, and 

side, and near its angle. draw it a little to one side. 

The condyloid process of To move the jaw, and to 

the lower jaw and capsular prevent the ligament of the 

ligament. jaw from being pinched. 

MUSCLES ABOUT THE NECK. 

The side of the chin and To draw the cheeks and skin 
integuments of the cheek. of the face downward.. 

The mastoid process, and as To move the head to one 
far back as the occipital su- side and bend it forward, 
ture. 

Explanation of Fig, 33. 

A, and h. sterna cleido mastoideus ; h, stylo hyoideus ; g, g, the 
two bellies of the digastricus ; f, sterno hyoideus ; i, the lower end 
oi the mastoideus ot the rii^ht side; e, omo hyoideus; d, the os 
hy aides ; c, the clavicle; k, complexus. 

Under the sterno cleido mastoid muscle, bounded by the letters a 
and b, in the opposite drawing, are a variety of beautiful, ribbon- 
like muscles, which are generally attached to the bone of the 
tongue, and the vocal box, — called the larynx, which is the protu- 
berance in the front part of the throat. Again, those muscles which 
arise about the base of the skull, under the ear, and anofle of the 
under jaw, are also inserted into the same places, — so that the bone 
and larynx are moveable fulcrums, — increasing the power of the 
muscles on either side, by changing their position. By this simple 
contrivance, the contraction of the muscles compress the windpipe, 
and thus increase, or vary the tone of the voice, hy diminishing the 
diameter of the air tube. Thus, bad singers in sounding a high note 
stretch back the head ; thus, too, unconsciously press the musical 
pipe into the smallest diameter. To sound a bass note, the chin is 
brought towards the breast, — and the same muscles are relaxed, 
and the diameter of the tube is at once increased. 



a^ 



ANATOMICAL CLASS BOOK. 



MUSCLES SITUATED BETWEEN THE LOWER JAW AND BONE 
OF THE TONGUE. 



JVame, 
Digastricus. 

Mylo-hyoideus. 

Genio-hyoideus. 

Genio-glossus. 

Hyo-glossus. 

Lingualis. 



Arises from 

A fossa at the root of the 
mastoid process. 

The inner surface of the 
jaw bone. 

The inside of the chin. 

The inside of the chin. 

The horn, basis, and carti- 
lage of the OS hyoides. 

The root of the tongue lat- 
erally. 



MUSCLES SITUATED 

Sterno-hyoideus. 

Omo-hyoideus. 

Sterno-thyroideus. 



Thyreo-hyoideus, or Hyo- 
thyroideus. 

Crico-thyroideus. 



BETWEEN THE OS HYOIDES AND TRUNK, 

The sternum and clavicle. 



Near the coracoid process 
of the scapula. 

The upper and inner part of 
the sternum. 

Part of the basis and horn 
of the OS hyoides. 

The side of the cricoid 
cartilaofe. 



MUSCLES SITUATED BETWEEN THE LOWER JAW AND OS 
HYOIDES, LATERALLY. 



Stylo-glossus. 

Stylo-hyoideus. 

Stylo-pharyngeus. 



Circumflexus, 

or 

Tensor palati. 

Levator palati mollis. 



The apex of the styloid 
process. 

The basis, and about the 
middle of the styloid process. 

The root of the styloid pro- 
cess. 

Near the Eustachian tube, 
and passes through the hamu- 
lus of the pterygoid process, 
to be 

The point of the os petros- 
um, the Eustachian tube, and 
sphsenoid bone. 



ANATOMICAL CLASS BOOK. 69 



MUSCLES SITUATED BETWEEN THE LOWER JAW AND BONE 
OF THE TONGUE. 

Inserted into Use, 

The lower and anterior part To draw the lower jaw 
of the chin. downward. 

The basis of the os hyoides. To move the os hyoides up- 
ward. 
The basis of the os hyoides. To move the os hyoides up- 
ward. 
The tongue, forming part To move the tongue in va- 
of its substance. rious directions. 

Into the tongue laterally. To draw the tongue down- 

ward and inward. 
The extremity of the tongue. To shorten and draw the 

tongue backward. 

MUSCLES SITUATED BETWEEN THE OS HYOIDES AND TRUNK. 

The basis of the OS hyoides. To draw the os hyoides 

downward. 
The basis of the os hyoides. To draw the os hyoides 

^ downward. 

The thyroid cartilage. To pull the thyroid cartilage 

downward. 
The side of the thyroid car- To raise the cartilage, and 
tilage. depress the bone. 

The inferior horn of the To pull the thyroid cartil- 
thyroid cartilage. age towards the cricoid. 

MUSCLES SITUATED BETWEEN THE LOWER JAW AND OS 
HYOIDES, LATERALLY. 

The side of the root of the To pull the tongue back- 
tongue, ward. 

The basis of the os hyoides. To draw the os hyoides up- 
ward. 

The edge of the pharynx, To dilate the pharynx, and 
and back of the thyroid carti- raise the cartilage, 
lage. 

The velum pendulum pal- To draw the velum pendu- 
ati. lum palati obliquely down- 

ward, and stretch it. 

The velum pendulum pal- To pull the velum pendu- 
ati, being expanded upon it. lum backward and upward. 



70 



ANATOMICAL CLASS BOOK. 



MUSCLES SITUATED ABOUT THE ENTRY OF THE FAUCES. 



JVame. 
Constrictor faucium. 

Palato-Pharyngeus. 



Azygos uvulsB.* 



Arises from 

Near the root of the tongue, 
on each side, and goes round 
to be 

The middle of the soft 
palate, goes round the entry 
of the fauces, the tendon of 
the circumflexus palati, and 
velum pendulum palati, to be 

The commissure of the ossa 
palati. 



MUSCLES SITUATED ON THE POSTERIOR PART OF THE PHARYNX. 



Constrictor pharyngius infe- 
rior. 

Constrictor pharyngius me- 
dius. 

Constrictor pharyngius su- 
perior. 



The cricoid and thyroid 
cartilages. 

The horns, and appendix of 
the OS hyoides. 

The pterygoid process, the 
lower jaw, and the cuneiform 
process of the os occipitis. 



MUSCLES SITUATED ABOUT THE GLOTTIS. 



Crico-arytsenoideus posti- 
cus. 

Crico-arytaenoideus later- 
alis, or obliquLis. 

Thyreo-arytsenoideus. 

Arytasnoideus obliquus.* 
Arytgenoideus transversus.^ 
Thyreo-epiglottideus. 
Arytaeno-epiglottideus. 



The cricoid cartilage poste- 
riorly. 

The side of the cricoid car- 
tilage. 

The back of the thyroid 
cartilage. 

The root of one arytsenoid 
cartilage- 
One of the arytsenoid car- 
tilages. 

The thyroid cartilage. 

The upper part of the ary- 
tsenoid cartilage laterally. 



ANATOMICAL CLASS BOOK. 71 



MUSCLES SITUATED ABOUT THE ENTRY OF THE FAUCES. 

Inserted into Use, 

The middle of the velum To raise the tongue, and 

pendulum palati, near the draw the velum toward it. 

uvula. 

The upper and posterior To contract the arch of the 

part of the thyroid cartilage. fauce. 



The extremity of the uvula. To shorten and raise the 

uvula. 



MUSCLES SITUATED ON THE POSTERIOR PAFvT OF THE PHARYNX. 

The middle of the pharynx. To compress part of the 

pharynx. 

The ambit of the pharynx. To compress the pharynx, 

and draw the os hyoides up- 
ward. 

The middle of the pharynx. To move the pharynx up- 
ward and forv/ard, and to 
compress its upper part. 



MUSCLES SITUATED ABOUT THE GLOTTIS. 

The back of the arytenoid To open the glottis, 
cartilage. 

The side of the arytsenoid To open the glottis. 
cartilage. 

The fore part of the arytse- To draw the arytesnoid car- 
noid cartilage. tilage forward. 

The extremity of the other. To draw them toward each 

other. 
The other arytsenoid carti- To shut the glottis. 
lage. 

The side of the epiglottis. To pull the epiglottis ob- 

liquely downward. 
The side of the epiglottis. To move the epiglottis out- 

ward. 



72 



ANATOMICAL CLASS BOOK. 



MUSCLES SITUATED ON THE ANTERIOR PART OF THE ABDOMEN. 



Obliquus descendens exter- 
nus. 

Obliquus ascendens inter- 
nus. 



Arises from 

The lower edges of the 
eight inferior ribs near the 
cartilages. 

The spinous processes of 
the three last lumbar verte* 
brae, back of the sacrum, and 
spine of the ilium. 



Fi^. 34. 




Transversalis abdominis. 

Rectus abdominis, 
Pyramidalis. 



The cartilages of the seven 
lower ribs, and the transverse 
processes of the four lower 
lumbar vertebrEe and spine of 
the ilium. 

Th3 outside of the sternum 
and xyphoid cartilage. 

The anterior upper part of 
the pubis. 



ANATOMICAL CLASS BOOK. 7S 



MUSCLES SITUATED ON THE ANTERIOR PART OF THE ABDOMEN. 

Inserted into Use, 

The linea alba, ossa pubis, To compress the abdomen, 
and spine of the ilium. 

The cartilages of all the To compress the abdomen, 
false ribs, linea alba, and pu- 
bis, and sternum, by a flat 
tendon. 

Explanation of Fig. 34. 
g. The obllquus internus, with its tendon divided, to show 
h. The pyramidalis. 

i. The rectus, abdominis. Beneath the internal oblique there is 
situated 

k. The transversalis abdorainalis, and 
I. The fascia transversalis. 

The tendons of the abdominal muscles, form junctions in front, 
where their broad white tendons meet, which are denominated 
lines ;— and that which runs exactly in the middle, from the lower 
point of the sternum, to the pubis, is the linea alba or white line. 
Again, the long abdominal muscles, lying each side of this linea 
alba, arc intersected, several times, between their two extremities, 
by similar tendinous lines, which, in reality, divides them into a 
chain of muscles. This structure has reference to increasing their 
power, by a series of contractions, along their course, which thereby 
answers a second intention, viz, preserving a symmetry of form. By 
consulting Fig. 34, page 72, both the vertical and transverse lines 
are discoverable. Statues representing action, invariably exhibit 
the muscles of the bowels thrown into ridges. Upon the princi- 
ples adverted to in the preliminary essay on myology, without these 
transverse bands, the bellies of the long recti muscle, in order to 
pull the chest, as in stooping for example, while seated in a chair, 
so as to bring the breast down to the knees, would have a bulk, by 
the process of contraction, equal to a two quart measure. By the 
introduction of the transverse tendinous lines, two vastly important 
results are obtained, — increased power and beauty of form. 

The linea alba throughout To compress the abdominal 
its whole length, and into the viscera, 
ensiform cartilage. 



The side of the symphysis To compress the abdomen, 

of the pubis. and bend the trunk. 

The linea alba, below the To assist the lower portion 

umbilicus. of the rectus. 
7 



74 



ANATOMICAL CLASS BOOK. 



MUSCLES SITUATED WITHIN THE PELVIS. 



JSPamt, 
Obturator internus. 

Coccygeus. 



Jlrisesfrom 

The foramen ovale, obtura- 
tor ligament, ilium, ischium, 
and pubis. 

The spinous process of the 
ischium. 



HUSCLES SITUATED WITHIN THE CAVITY OF THE ABDOMEN. 



Quadratus lumborum. 
Psoas parvus. 

Fig. 35. 



The posterior part of the 
spine of the ilium. 

The transverse process of 
the last dorsal vertebra. 




Explanation of Fig. 35 

K. The iliaciis internum. 
R. The psoas magnus. 
S. The obturator exter- 

nus. 



ANATOMICAL CLASS BOOK. 75 



MUSCLES SITUATED WITHIN THE PELVIS. 

Inserted into Use. 

A large pit between the tro- To roll the femur obliquely 
chanters of the femur. outward. 

The extremity of the sa- To move the coccyx for- 
crum and os coccygis, ward and inward. 



MUSCLES SITUATED WITHIN THE CAVITY OF THE ABDOMEN. 

The transverse apophyses To support the spine and 
of the loins and last spurious draw it to one side, 
rib. 

The brim of the pelvis, To bend the loins forward, 
near the place of the aceta- 
bulum. 

On the inside of the broad hip bone, os innominatum, seen on the 
opposite page, Fig. 35, and also running up by the side of the lumbar 
vertebrae, three muscles have their origin, — that bear a highly im- 

every other place in the system, a two fold intention is answered. 
First, — these three muscles are cushions, — on which the coils of 
the intestines rest. Without them, some other proviiicn would have 
been necessary, as a soft bed is indispensable for theji, in the violent 
exercises of running, leaping, or even walking. Secondly, the 
tendons of the psoas magnns and iliacus internus, are sent over the 
brim of the pelvis, to wind down the inside of the groin, close to the 
bone, to reach the backside of the thigh bone, where they are fast- 
ened. Obscure as they are, these muscles, when standing on our 
feet, maintain the body in an erect position. If we desire to move 
forward, these muscles lift up the whole limb, — and when they re- 
lax, the foot strikes the ground again. If, while sitting, the knee is 
raised towards the chest, the act is accomplished by these two mus- 
cles. In walking and running, therefore, as they are the Ufters-up 
of the leg, their services could not be dispensed with. A lumbar 
abscess, a painful disease, wholly forbidding the movement of the 
limb of the side in which it occurs, is a collection of matter under 
the psoas magnus, and next to the back bone, near the line R, on 
the plate. As the abscess cannot be very safely discharged by a 
surgical operation, through the muscles ol the back, in protracted 
cases, the matter sometimes follows the muscles, quite into the limb, 
and forces its way down, even to the knee, before it escapes. This 
dreadful disease has been induced, by lying on the damp ground, 
after freely exercising; and by unnecessary feats of strength, in 
lifting burdens, in the careless days of youthful vigor. 



76 



ANATOMICAL CLASS BOOK. 



JVame. 
Psoas magnus. 

lliacus internus. 



Arises from 

The bodies and processes 
of the last dorsal and all the 
lumbar vertebrae. 

The internal surface of the 
spine of the ilium. 



MUSCLES SITUATKD ON THE ANTERIOR PART OF THE THORAX. 



Pectoralis major. 



The clavicle, sternum and 
seven true ribs. 



Fig. 36. 




Subclavius. 
Pectoralis minor. 



The cartilage of the first rib. 

The third, fourth, and fifth 
ribs. 



ANATOMICAL CLASS BOOK. 77 

Inserted into Use. 

The OS femoris, a little be- To bend the thigh forward, 
low the trochanter minor. 

The femur in common with To assist the psoas magnus. 
tlie psoas magnus. 

MUSCLES SITUATED ON THE ANTERIOR PART OF THE THORAX. 

The upper and inner part of To draw the arm forward, 
the humerus. or obliquely forward. 

Explanation of Fig. 36. 

a. The pectoralis major. 

b. b. The obliqiuis abdominis externus descendens: beneath these 
muscles the following: — 

c. The pectorahs minor, 

d. The serratus magnus anticus. 

e. The external intercostal muscles. 
/. The internal intercostal muscles. 

g. The obliquus abdominis internus ascendens. 

By returning to the anatomy of the ribs, it is there shown that 
they are constructed to move : — breathing is effected by increasing 
and diminishing; the capacity of the chest, as the lungs are inflated 
or collapsed. To carry on this operation, an appropriate class of 
muscles take their rise on, and about the libs and sternum, to be ex- 
clusively engaged in this respitory action. Between the edges of 
the ribs, short oblique muscles, one the internal and the other the 
external, crossing each other, like suspenders on a man's back, — 
are untiring in their labors : — when they contract, the ribs are 
brought together; and when relaxed, the diameter of the chest is 
enlarged. All the muscles on the breast and sides, are remotely 
respitory agents. If the arms are fixed, by their contraction the 
ribs are drawn outwardly. Asthmatic persons, because the small 
intercostal muscles do not relax enough, bring the pectoral muscles 
to their aid, hy raising their hands and holding on to a door, or a 
beam, for example, above the head. This enables them to pull 
open, as it were, the bottom of the chest. Ladies often swoon and 
sometimes drop down dead instantly, in consequence of lacing the 
chest so tightly, that the ribs cannot possibly move. 



The under surface of the To move the clavicle down- 
clavicle, ward. 

The coracoid process of the To roll the scapula, 
scapula. 

7* 



78 



ANATOMICAL CLASS BOOK. 



J>tame, 
Serratus major anticus. 



Arises from 
The eight superior ribs. 



MUSCLES SITUATED BETWEEN THE RIBS AND WITHIN THE 
THORAX. 



Intercostales externi. 
Intercostales interni. 



Triangularis, or 
Sterno-costalis. 



The lower edge of each 
upper rib. 

Like the former, their fibres 
are directed from behind for- 
ward. 

The middle and inferior 
part of the sternum. 



MUSCLES SITUATED ON THE ANTERIOR PART OF THE NECK, 
CLOSE TO THE VERTEBRA. 



Longus colli. 



Rectus internus capitis ma- 
jor. 

Rectus internus capitis mi- 
nor. 

Rectus capitis lateralis. 



The bodies of the three 
upper dorsal and transverse 
processes of the four last 
cervical. 

The transverse processes of 
the five last cervical vertebrae. 

The fore part of the atlas. 

The transverse process of 
the atlas. 



MUSCLES SITUATED ON THE POSTERIOR PART OF THE TRUNK. 



Trapezius, or Cucullaris. 



Latissimus dorsi. 



Serratus posticus inferior- 



The OS occipitis and the 
spinous processes of all the 
vertebrae of the neck and 
back. 

The spine of the ilium spin- 
spinous process of the sacrum, 
lumbar and inferior dorsal ver- 
tebrae ; adheres to the scapula 
and inferior false ribs. 

The spinous processes of 
the two last dorsal and three 
lumbar vertebrce. 



ANATOMICAL CLASS BOOK. 79 

Inserted into Usq, 

The base of the scapula. To bring the scapula for- 

ward. 



MUSCLES SITUATED BETWEEN THE RIBS AND WITHIN THE 
THORAX. 

The superior edge of each To elevate the ribs, 
lower rib. 



The cartilages of the five To depress the cartilages 
last true ribs. of the ribs. 

MUSCLES SITUATED ON THE ANTERIOR PART OF THE NECK, 
CLOSE TO THE VERTEBRA. 

The anterior tubercle of the To pull the neck to one 
aentatus. side. 

The cuneiform process of To bend the head forward 
the osoccipitis. 

The OS occipitis, near the To assist the former. 
conayJoid process. 

The OS occipitis, near the To move the head to one 
mastoid process. side. 

MUSCLES SITUATED ON THE POSTERIOR PART OF THE TRUNK. 

The clavicle part of the To move the scapula, bend 
acromion, and the spine of the the neck, and pull the head 
scapula. backward. 

The OS humeri, between its To draw the os humeri 

two tuberosities m the edge backward, and to roll it upon 

of the groove for the tendon its axis, 
of the biceps muscle. 

The lower edge of the three To draw the ribs outward, 
or four lowermost ribs, near downward, and backward. 
their cartilages. 



80 



ANATOMICAL CLASS BOOK. 



Rhomboideus. 

Splenius. 

Serratas superior posticus. 

Spinalis dorsi. 



Levatores costarum, or 
Supra-cotales. 

Sacro-lumbalis. 



Arises from 

The spinous processes of 
the three last cervical, and 
four first dorsal vertebras. 

The spines of the four last 
cervical, and four superior dor- 
sal vertebrse. 

The spinous processes of 
the three last cervical, and two 
superior dorsal vertebrse. 

Two spinous processes of 
the loins, and three lower of 
the back. 

The transverse processes of 
the last cervical and the dor- 
sal vertebrse. 

The sacrum,, spine of the 
ilium, and the spinous and 
transverse processes of the 
lumbar vertebrse. 



Fiff. 37. 




Explanations of 
Fig. 37. 

a. The trapezi- 
us. 

h. The latissimus 
dorsi. 

c. The rhomboi- 
deus minor. 

d. The rhomboi- 
deus major. 

e. The serratus 
posticus inferior. 

/. The levator 
anguli scapulae. 

Blocks were in- 
troduced to repre- 
sent the figure in a 
horizontal position, 
that the muscles 
might be more dis- 
tinctly seen. 



ANATOMICAL CLASS BOOK. 



81 



Instated into 
The basis of the scapula, at 
its upper and lower part. 

The two first cervical verte- 
brae, and the side of the os 
occipitis. 

The second, third, and fourth 
ribs, by three neat fleshy 
tongues. 

All the spinous processes of 
the back, except the first. 

The angles of the ribs. 



Use. 
To move the scapula up- 
wards and backward. 

To move the head back- 
ward, and also to one side. 

To expand the thorax, by 
elevating the ribs. 

To extend the vertebrae. 



To lift the ribs upward. 



The lower edge of each rib, 
by a flat tendon. 



To draw the ribs down- 
ward, to move the body upon 
its axis, to assist the longissi- 
mus dorsi, and to turn the neck 
back, or to one side. 



All the muscles of the back, clearly defined in Fig. 37, on the 
opposite pa2;e, are broad, thin, and generally produce the slow mo- 
tion of the limbs. In the middle of the trapezius, marked a, is a 
white line, where the fibres of the muscle, on either side meet and 
adhere to the spinous processes of the bones of the neck. On this 
line, in quadrupeds, is placed a powerfully strong cord, by the far- 
riers called paxwax, — but by anatomists — ligamentum nuchce, 
which, being attached to the back bone, between the shoulders, pre- 
vents their heavy head from drooping to the ground, It will not re- 
lax : — when they drink or feed, on a level with their feet, the nose, 
even by a voluntary efibrt, barely reaches to the earth. 



82 



ANATOMICAL CLASS BOOK. 

Fig. 38. 




ANATOMICAL CLASS BOOK. 83 

Explanation of Fig. 38. 
a, upper portion of the trapezius ; i. sterno cleido mastoideus ; d. 
the deltoid portion of the trapezius; f. the latissimus dor si ; 
n. n. n. n. portions of the latissimus, rising by dio;itations from the 
ribs ; g. and h. tendinous continuation of the latissimus into the 
fibres of the gluteus maximus ; /?. the deltoides muscle, to raise the 
arm ; /r, e, m, the infra spinatus, belonging to the shoulder; c, the 
clavicular portion of the deltoides ; /, the intermingling of the fibres 
of the gluteus maximus, and latissimus dorsi. 



The artist was particularly fortunate in delineating the muscles in 
the accompanying diagram. No plate could more accurately show 
the relation which one bears to the other, nor more truly represent 
the converging fibres, all centering in the tendons. As in the de- 
monstration of the eye, it can also be said here, — that there are 
coats of muscles on the back and sides. One overlaps the edges of 
another, in such a perfect manner, as to leave no deep spaces : — an 
even covering is thus spread over the skeleton. The latissimus 
dorsi. marked/, is one of the most beautiful in the body; and its 
utility is proved every moment. Jts office is tobiing down the hand. 
Before man invented instruments which have superseded, to consid- 
erable extent, the primitive use of the hand, in some particulars, — 
his fist was a mallet, — the arm the handle, and this muscle, the 
power that gave force to the blow. Those mechanics who are con- 
stantly using hammers, and axes, increase its size and strength, 
amazingly. If the aim, on the other hand, be firmly fixed, in a 
horizontal position, the digitations marked n, n, 7i, n, by their strong 
hold upon the false ribs, would open the bottom of the chest, quite 
effectually. Over the shoulder joint, and from thence, running to 
the middle of the arm bone, is a splendid muscle, — the deltoides, 
marked /?, which raises the arm to a level with the shoulder; its 
lateral portions, even carry the elbow very much above the level 
of their origin. If it were divided, no remaining muscle could per- 
form its otfice. Just above f, winding partially under the deltoides, 
is that muscle which extends the arm. The name of triceps exten- 
sor cubiti \? given it, because it arises by three heads, which uniting 
in one tendon, passes the elbow joint, on the back of the arm, to be 
inserted into the ulna, or, as the bone is sometimes called, the cubit. 
Lastly, k, e, m, directs the eye to the i?}fra spinatus, arising on the 
external surface of the shoulder blade, and inserted into the arm 
bone. By its contraction, the arm is raised a very little, and carried 
backward; — its tendon, as it passes over the shoulder joint, adheres 
to the capsular ligament and keeps it drawn out, so that it may not 
be pinched, by the rolling motion of the ball in the socket. 



84 



ANATOMICAL CLASS BOOK. 



Longissimus dorsi. 
Complexus. 



Trachelo-mastoideus. 
Levator scapulas. 
Semi-spinalis dorsi. 
Multifidus spinae. 



Semi-spinalis colli, or 
Spinalis cervicis. 

Transversalis colli. 



Rectus capitis posticus ma- 
jor. 

Rectus capitis posticus mi- 
nor 

.Obliquus capitis superior. 

Obliquus capitis inferior. 

Scalenus. 

Interspinales. 

Inter-transversales. 



Arises from 

The same parts as the for- 
mer, and by one common 
broad tendon. 

The transverse processes of 
the four inferior cervical, and 
seven superior dorsal verte- 
brae. 

The transverse processes of 
the five lower cervical and 
three upper dorsal vertebrae. 

The transverse processes of 
the four superior cervical ver- 
tebrae. 

The transverse processes of 
the 7th, 8th, 9th, and 10th 
dorsal vertebrae. 

The sacrum, ilium, oblique 
and transverse processes of 
the lumbar, the transverse of 
the dorsal, and four cervical 
vertebrae. 

The transverse processes 
of the six upper dorsal verte- 
brae. 

The transverse processes of 
the five upper dorsal verte- 
brae. 

The transverse process of 
the second cervical vertebrae. 

The first vertebrae of the 
neck. 

The transverse process of 
the atlas. 

The spinous process of the 
dentatus. 

The upper surface of the 
first and second rib. 

Between the spinous pro- 
cesses of the six inferior cer- 
vical vertebrae. 

Between the transverse 
processes of the vertebrae. 



ANATOMICAL CLASS BOOK. S5 

Inserted into Use. 

The transverse processes of To stretch the vertebrse ot 

all the dorsal and one cervical the back, and keep the trunk 

vertebra, erect. 

The middle of the os occi- To draw the head back- 

pitis, at its tubercle. ward. 



The OS occipitis, behind the To draw the head backward, 
mastoid process of the tempo- 
ral bone. 

The upper angle of the To move the scapula for- 
scapula. ward and upward. 

The spinous processes of To extend the spme ob- 
the four superior dorsal and liquely backward, 
the last cervical vertebras. 

The spinous processes of the To extend the back, and 
lumbar dorsal, and cervical draw it backward, or to one 
vertebra^, except the atlas. side, and prevent the spine 

from being too much bent for- 
ward. 

The spinous processes of To stretch the neck ob- 
the five middle cervical. liquely backward. 

The transverse processes of To turn the neck obliquely 
the cervical vertebrae backward, and to one side. 

The lower ridge of the os To extend the head, and 

occipitis. draw it backward, 

The OS occipitis at its tu- To assist the rectus major, 
beicle. 

The end of the lower occi- To draw the head back- 

pital ridge. ward. 

The transverse process of To draw the face to one 

the atlas. side. 

The transverse processes of To move the neck forward, 

the cervical vertebrae. or to one side. 

The spinous processes of To draw the spinous pro- 

the vertebrae above. cesses towards each other. 

The transverse processes of To draw the transverse pro- 
the vertebrae above. cesses towards each other. 



86 



ANATOMICAL CLASS BOOK. 



MUSCLES OF THE SUPERIOR EXTREMITIES. 



JVame, 
Supra-spinatus. 

Infra spinatus. 



Jlrisesfrom 

The basis, spine, and upper 
end of the scapula. 

The cavity below the spine 
of the scapula. 



Fig. 39 




Explanation of Fig, 39. 
a. The supra-spinatus. 
h. The intra spinatus. 

c. The teres minor. 

d. The teres major. 

e. The latissimus dorsi. 
/. The deltoid. 

g. The triceps extensor cubiti. 



Teres minor. 
Teres major. 
Deltoides. 
Coraco brachialis. 



The inferior edge of the 
scapula. 

I'he inferior angle and edge 
of the scapula. 

The cavicle, and the acro- 
mion and spine of the scapula. 

The coracoid process of the 
scapula. 



ANATOMICAL CLASS BOOK. 



MUSCLES OF THE SUPERIOR EXTREMITIES. 

Inserted into Use, 

A large tuberosity at the To raise the arm. 

head of the os humeri. 
The upper part of the same To roll the os humeri out- 

tuberosity. ward. 

'Anatomists have sought for an explanation of the superioiity of 
the right hand, over the left, in the muscles, arteries and nerves of 
the arm ; but no very satisfactory light has been thrown upon the 
subject. At one tinje, it was a common mode of getting over the 
difficulty, to say that the preference we give to the right hand, arises 
from its superior strength; and that quality is owing to the man- 
ner in which the artery arises from the arch of the aorta, just above 
the heart. There is certainly a considerable difference in the size 
of the arteries in the two arms. The right in this respect, being 
the largest, derives its blood more directly from the fountain head. 
As the power of the muscle actually depends on the blood circulat- 
ed in its substance, it was very natural to refer the origin of its su- 
perior force to this cause. Here the inquiry has rested, so far as 
anatomical demonstration is concerned. But a formidable objection 
to that old fashioned theory arises, when we find a left-handed man. 
whose arm does not diflfer essentially from any other person's left arm, 
and ambidexters, men using one hand just as well as the other, for 
example, in writing, throwing balls, turning a gimblet, using a cabi- 
net-maker's plane, die, seem to be entirely out of the reach of the 
old stereotyped theory about the artery. The preference, given to 
the right hand, conduces to its muscular development; it is both 
larger, and stronger, by use. So it is with the right foot, and hence 
the extreme difficulty, with some, of wearing a pair of shoes made 
on one last. 

The evidence is pretty conclusive, from the universality of the 
law, which embraces all the inferior animals, as well as man, that it 
was expressly designed by the Creator, that the limbs on one side of 
the body should possess certain physical advantages over the other. 
Both rapidity of motion, and strength, are thus combined, constantly 
improved upon by practice, and a certain mechanical excellence 
is thus bestowed, without which we should be incompetent to 
the discharge of those duties which devolve upon us. 

The greater tuberosity of To assist the former, 
the humerus. 

The side of the groove for To assist in rotating the 

the long tendon of the biceps, arm. 

The anterior and middle To raise the arm. 
part of the os humeri. 

The middle and inner side To roll the arm forward and 

of the OS humeri. upward. 



88 



ANATOMICAL CLASS BOOK. 



MUSCLES SITUATED ON THE OS HUMERL 



JVame, 
Subscapularis. 

Biceps flexor cubiti. 



Brachialis internus. 
Triceps extensor cubiti. 

Anconeus. 



Arises from 

The basis, superior and in- 
ferior edge of the scapula. 

Two heads, one from the 
coracoid process, the other, 
called the long head, from the 
edge of the glenoid cavity 
of the scapula. 

The OS humeri at each side 
of the tendon of the deltoides. 

The neck of the scapula, 
and the neck and middle of 
the humerus. 

The external condyle of 
the humerus. 



MUSCLES SITUATED ON THE FORE ARM. 

Supinator radii longus. 



Extensor carpi radialis lon- 
gior. 

Extensor carpi radialis bre- 
vier. 

Extensor digitorum commu- 
nis. 

Extensor minimi digiti. 

Extensor carpi ulnaris. 
Flexor carpi ulnaris. 
Palmaris longus. 

Flexor carpi radialis, 
Pronator radii teres. 

Supinator radii brevis. 



The external condyle of the 
humerus. 

The external condyle of the 
humerus. 

The external condyle of the 
humerus. ;, 

The external condyle of the 
OS humeri. 

The outer condyle of the 
humerus. 

The outer condyle of the os 
humeri. 

The inner condyle of the 
humerus and olecranon. 

The internal condyle of the 
OS humeri. 

The internal condyle of the 
OS humeri. 

The internal condyle of the 
humerus and coronoid process 
of the ulna. 

The outer condyle of the 
humerus and edge of the uln^. 



ANATOMICAL CLASS BOOK. 



89 



MUSCLES SITUATED ON THE OS HUMERI. 



Use. 
To roll the arm inward. 



Inserted into 

The protuberance at the 
head of the os humeri. 

The tuberosity at the upper To bend the fore arm, 

end of the radius, at its fore which it does with great 

part, and a little below its strength, and to assist the 

neck. supinators. 

The coronoid process of the To assist in bending the 

ulna. fore arm. 

The upper and outer part To extend the fore arm. 
of the olecranon. 

The back part or ridge of To assist in extending the 

the ulna. fore arm. 



MUSCLES SITUATED ON THE FORE ARM. 



The radius near the styloid 
process. 

The metacarpal bone of the 
fore finger. 

The metacarpal bone of the 
middle finger. 

The back of all the bones 
of the fingers. 

The second joint of the 
little finger. 

The metacarpal bone of the 
little finger. 

The OS pisiforme, at its fore- 
part. 

The annular ligament of the 
wrist, and there forms the 
aponeurosis of the hand. 

The metacarpal bone of the 
fore finger. 

The outer ridge of the radi- 
us, about the middle of its 
length. 

The anterior, inner, and 
upper part of the radius. 



To assist in turning up the 
palm of the hand. 
To extend the wrist. 

To assist the former. 

To extend the fingers. 

To assist in extending the 
fingers. 

To assist in extending the 
wrist. 

To assist in bending the 
hand. 

To bend the hand. 

To bend the hand. 

To roll the hand inward. 



To roll the radius outward, 
and assist the anconeus. 



8* 



90 



ANATOMICAL CLASS BOOK. 



JVa me , Arises from 

Extensor ossis metacarpi The middle of the ulna, in- 
pollicis manus. terosseous ligament and radius. 



Fig. 40. 



Fig. 41. 



W^ 



'l^il 



^1 




ANATOMICAL CLASS BOOK. 91 

Inserted into Use. 

The OS trapezium, and first To stretch the first bone of 
bone of the thumb. the thumb outward. 



Explanation of Fig, 40. 
/. extensor digitorum communis, for extending the fingers; A, ex- 
tensor proprius minimi digiti, to extend the little finger : /, where 
it unites with others; i, extensor carpi ulnaris ; Z, anconeus, ex- 
tensor ossis metecarpi pollicis ; e, extensor primi ititernodii pollicis ; 
e, extensor secundi internodii pollicis; d, indicator ; g, annular 
ligament of the wrist ; m, will he recognised ; kj an abductor of 
the Uttle finger ; e, supinator radii longus. 



Explanation of Fig. 41. 
a, pronator teres ; b, flexor carpi radialis ; c, d, pahnaris longus ; 
e, flexor carpi ulnaris ; g, flexor carpi radialis longoir. 

Between the elbow and ends of the finorers there are about fifty 
muscles. Some of them, — particularly those by the sides of the fing- 
ers, are quite short and delicate. All the quick short motions of the 
fingers are made by them. Their name, musculi fidicinales, 
fiddhng muscles, in old books, is quite appropriately given, because 
the strings of the instrument are operated upon almost entirely by 
them. A back and front view of the fore arm is presented in 
the opposite page. Fig's 40, and 41, in which all the long mus- 
cles, on the inside flexors, and on the back of the arm exten- 
sors, may be very accurately observed. Just under the skin, a 
silvery, tough membrane, like a silk case, is drawn closely over the 
muscles, to keep them from swelling too much, in their contractions. 
As before remarked, the strength which a muscle exerts, by being 
pressed down to the bone, when in action, is increased a hundred 
fold. The beauty and proportion of the limb is wholly preserved 
by the case, which is called fascia. It is taken away, in these 
plans, in order to show more distinctly the parts below. 



92 



ANATOMICAL CLASS BOOK. 



JVame . Arises fro m 

Extensor primi internodii. Near the middle of the ulna> 

interosseous ligament, and 
radius. 
Extensor secundi interne- The back of the ulna and 
dii. interosseous ligament. 

Indicator. The middle of the ulna. 



Fig. 42. 



Fig. 43. 




mi 



PI 



\ 



^ 



ANATOMICAL CLASS BOOK. 



93 



Inserted into 

The convex part of the 
second bone of the thumb. 

The third and last bone of 
the thumb. 

The metacarpal bone of the 
fore finder. 



Use. 

To extend the second bone 
of the thumb outward. 

To stretch the thumb ob- 
liquely backward. 

To extend the fore finger. 



Explanation of Fig, 4*2. 
d, e, flexor digitorum suhlimis, attached to the second bone of 
each finger, by four tendons, to bend the second joint, — /, h, flexor 
longus policis inanus, to bend the thumb ; a, b, c, pronator teres, 
to pronate the hand ; g, a slit in the tendons of the flexor digitorum 
for the passage of four other tendons of another muscle which go 
to the points of the fingers, for bending the last joint. 



Explanation of Fig. 43. 
c, d, d, the pronator quadratus, is one of two small muscles 
for pronating the hand ; a, 6, the other, — pronator teres. 



In Fig's. 42, and 43, the muscles are distinctly engraven, which 
roll the fore arm m supination dindi pronation. By turning a key 
in a door-lock, both sets are called into action, and it is recommend- 
ed to the reader to do it, and at the same time to feel the contractions 
of the muscles with the other hand. Fig. 43, the bones are made 
so plain, as to show the exact relation which the pronators have to 
them. On the other, Fig. e, points to the four tendons of the 
muscle that bends the last bone of the fingers. Looking back to Fig. 
41, page 90, it is there concealed by the flexor of the second bone of 
the fingers. This, in order to reach its place of destination, pierces, 
as it were, the tendons of the upper muscle, and thus sends its own 
tendons onward, through the slit. 



94 



ANATOxMICAL CLASS BOOK, 



JVame. 
Flexor digitorum sublimis. 



Flexor digitorum profundus 
vel perforans. 

Flexor longus poUicis. 

Pronator radii quadratus., 



Arises from 

The inner condyle of the os 
humeri, coronoid process of the 
ulna, and upper part of the 
radius. 

The upper part of the ulna, 
and interosseous ligament. 

The upper and fore part of 
the radius. 

The inner and lower part 
of the ulna. 



MUSCLES SITUATED CHIEFLY ON THE HAND. 



Lumbricales. 

Flexor brevis pollicis manus. 

Opponens pollicis. 
Abductor pollicis manus. 
Abductor pollicis manus. 
Abductor indicis manus. 
Palmaris brevis. 
Abductor minimi digiti man- 

B. 

Abductor minimi digiti. 
Flexor parvus minimi digiti. 
Interossei interni, and 
Interossei externi. 



The tendons of the flexor 
profundus. 

The OS trapezoides, liga- 
ment of the wrist, and the os 
magnum. 

The OS scaphoides and liga- 
ment of the wrist. 

The annular ligament, and 
OS trapezium. 

The metacarpal bone of the 
middle finger. 

The first bone of the thumb, 
and OS trapezium. 

The annular ligament, and 
palmar aponeurosis. 

The annular ligament and 
OS pisiforme. 

The OS cuneiforme and car- 
pal ligament. 

The annular ligament and 
OS cuneiforme. 

The metacarpal bones. 



MUSCLES OF THE INFERIOR EXTREMITIES. 

Pectinalis. 



The anterior edge of the 
OS pubis. 



ANATOMICAL CLASS BOOK, 



95 



Inserted into 

The second bone of each 
finger, after being perforated 
by the tendons of the profun- 
dus. 

The fore part of the last 
bone of each of the fingers. 

The last joint of the thumb. 

The radius opposite to its 
orio'in. 



Use. 

To bend the second joint of 
the fingers upon the first, and 
the first upon the metacarpal 
bones. 

To bend the last joint of the 
fingers. 

To bend the last joint of the: 
thumb. 

To roll the radius inward. 



MUSCLES SITUATED CHIEFLY ON THE HAND. 



The tendons of the extensor 
digitorum communis. 

The ossa sesamoidea and 
second bone of the thumb. 



To bend the first and extend 
the second phalanx. 

To bend the second joint of 
the thumb. 



The first bone of the thumb. To bend the thumb. 



The root of the first bone of 
the thumb. 

The root of the first bone of 
the thumb. 

The first bone of the fore 
finger posteriorly. 

The metacarpal bone and 
skin of the little finger. 

The first bone of the little 
finger. 

The metacarpal bone of the 
little finger. 

The first bone of the little 
finger. 

The sides of the metacarpal 
bones. 



To draw the thumb from 
the fingers. 

To pull the thumb toward 
the fingers. 

To move the fore finger to- 
wards the thumb. 

To contract the palm of the 
hand. 

To draw the little finger 
from the rest. 

To move that bone toward 
the rest. 

To draw the little finger 
from the rest. 

To extend the fingers, 
and move them toward the 
thumb. 



MUSCLES OF THE INFERIOR EXTREMITIES. 

To bend the thigh. 



The upper part of the linea 
aspera of the femur. 



96 



ANATOMICAL CLASS BOOK. 



JStame, 
Adductor longus femo- 

s. 

Adductor brevis femo- 



ris. 



Adductor magnus femo- 



ris. 



Arises from 
The upper and fore part of 
the pubis. 

The fore part and ramus of 
the OS pubis. 

The lower and fore part of 
the ramus of the pubis. 



Fig. 44. 




Explanation of Fig. 44, 

c. The gluteus medius. 

d. The pyriformis. 

e. The geminus superior. 
/. The geminus interior. 
g. The obturator internuSo 
g*. The quadrator femoris. 
h. The biceps flexor cruris„ 
i. The semitendinosus. 

k. The semimembranosus 

I. The superficial gluteal 
artery and nerve. 

m. The greatischiaticnerve. 

n. The ischiatic artery. 

0. The popliteal nerve. 

p. The fibular or peroneat 
nerve. 

q. The popliteal vein. 

r. The popliteal artery. 

s. The internal pudic artery 
vein, and nerve. 

t, t. The muscles on the 
anterior part of the thigh. 



ANATOMICAL CLASS BOOK. 97 

Inserted into Use, 

The middle and back part To bend the thigh, 
of the linea aspera. 

The inner and upper part To bend the thigh, and 

of linea aspera. move it inward. 

The whole length of the To move the thigh inward, 

linea aspera. and assist in bending it. 



Besides the muscles, nerves, veins, tendons, bands, and ligaments, 
there are absorbents — an exceedingly minute classof tubes, of the 
utmost importance in the animal economy. From the inner edge 
of the great toe, to the groin, there is a chain of absorbentSj le- 
sembling, when magnified by a lens, a multitude of threaded eggs. 
It is the office of the absorbents to pick up whatever mii^ht otherwise 
have been wasted, and return it to (he heart, that it Uiay be appio- 
priated to the wants of the body. These egg-shaped particles are 
receiving oroans, immensely larger than the tubes which bring into 
them the fluids they suck up about the muscles. By the agency of 
these small bodies, which are greedy to .-eize wliatever is piesented 
to them, the physician is able to convey medicines into the circula- 
tion, when they could not be taken into the siomach. It may be 
desirable to salivate, or in other words, to increase the quantity of 
fluid in the mouth, in order to overcome some local disease, but as 
mercuiy, in the form best adapted to produce that eftect, would be 
injurious, to swallow, it is rubbed on the skin, over these lymphat- 
ics ov abs or bents, he'in^ called by either name, which at once convey 
it into the blood; — but being oflensive and injuiious to the body, ano- 
ther set of vessels discover the presence of the unwelcome visitor, and 
speedily go to work to throw it out of the system. In the case of mercu- 
ry, it is conveyedout at the mouth, and the great flow of saliva, which 
keeps up a constant spitting, is nothing more than nature's scheme to 
wash away the noxious matter. 

These absorbents sometimes suck in a poisonous matter: — here 
an action at once takes place, of an extraordinary character. It 
seem as though the lymphatic thus loaded, was conscious of 
its destructive burden, and instead of allowing it to flow to the 
next one, towards the heart, it inflames, bursts open, and discharg- 
es its contents in the form of a sore. Sometimes this ulceration may 
extend to the neighboring lymphatic, and so the disease be propagated 
even into the cavities of the body. If a serpent's fang wound the skin, 
the absorbents convey the venom onward, like couriej-s, to head-quar- 
ters, the heart, whence it is distributed at once through the sys- 
em. If a bee stings, the poison is ushered along by the same organs. 

The absorbents are exceedingly active agents, but so small, that 
their existence was unknown, a long time after the discovery of th§ 
circulation. 

9 



98 



ANATOMICAL CLASS BOOK. 



JVame, 
Obturator externus. 

Gluteus maximus. 



Gluteus medius. 
Gluteus minimus. 

Pyriformis. 
Gemini. 
Quadratus femoris. 



Arises from 

The obturator ligament, and 
half of the thyroid hole. 

The spine of the ilium, pos- 
terior sacro ischiatic ligaments, 
and OS sacrum. 

The spine and superior sur- 
face of the ilium. 

The outer surface of the 
ilium and border of its great 
notch. 

The anterior part of the os 
sacrum. 

The spine and tuberosity of 
the ischium. 

The tuberosity of the is- 
chium. 



MUSCLES SITUATED ON THE THIGH. 



Facialis, or 

Tensor vaginae femoris. 

Sartorius. 

Gracilis. 

Rectus femoris, or 
Rectus cruris. 

Vastus externus. 

Vastus internus. 

Cruralis, or Crurseus. 

Semi-tendinosus. 

Semi-membranosus. 



The upper spinous process 
of the ilium. 

The upper spinous process 
of the ilium. 

The fore part of the ischium 
and pubis. 

The lower spinous process 
of the ilium, and edge of the 
acertabulum. 

The root of the great tro- 
chanter, and linea aspera. 

The trochanter minor, and 
the linea aspera. 

The anterior part of the 
lesser trochanter. 

The tuberosity of the is- 
chium. 

The tuberosity of the is- 
chium. 



ANATOMICAL CLASS BOOK. 



99 



Inserted into 

The femur near the root of 
the great trochanter. 

The upper part of the linea 
aspera of the femur. 

The great trochanter of the 
OS femoris. 

The root of the great tro- 
chanter. 

A cavity at the root of the 
great trochanter. 

The same cavity as the 
pyriformis. 

A ridge between the two 
trochanters. 



Use, 

To pull forward, and rotate 
the thigh. 

To extend the thigh, and 
assist in its rotatory motion. 

To assist the gluteus maxi- 
mus. 

To assist the two former. 



To roll the thigh outward. 
To roll the tliigh outward. 
To move the thigh outward. 



MUSCLES SITUATED ON THE THIGH. 

To Stretch the fascia. 



The inner side of the mem- 
branous fascia which covers 
the thigh. 

The upper and inner part 
of the tibia. 

The upper and inner part 
of the tibia. 

The upper and fore part of 
the patella. 

The upper and lateral part 
of the patella. 

The upper and inner part of 
the patella. 

The upper part of the patel- 
la. 

The upper and inner part of 
the tibia. 

The back part of the head 
of the tibia. 



To bend the leg inward. 
To bend the leg. 
To extend the leg. 

To extend the leg. 

To extend the leg. 

To extend the leg. 

To bend and draw the leg 
inward. 
To bend the leg. 



100 



ANATOMICAL CLASS BOOK. 



Fig. 45. 




Explanation of Fig. 
45. 

a. The tensor vag- 
inae femoris. 

b. The sartorius. 

c. The rectus fe- 
moris. 

d. The vastus ex- 
ternus. 

e. The vastus in- 
tern us. 

/. The pectinalis. 

g. The adductor 
^ longus. 

h. The adductor 
magnus. 

i. The gracilis. 

k. Ihacus internus. 

Z. The anterior 
crural nerve. 

771. The femoral ar- 
tery. 

71. The femoral 
vein. 

1. The externa] ep- 
igastric artery. 

2. The external cir- 
cuinflexa ilii. 



JVame. 
BicoDS fluxor cruris. 



Arises from 
The tuberosity of the is- 
chiuni. 



Popliteu?. 



The external condyle of the 
thio^h bone. 



ANATOMICAL CLASS BOOK. 101 



To a person unaccustomed to anatomical language, the names of 
the muscles will undoubtedly appear exceedingly unmeaning, and 
diflficult to pronounce. This is true, as respects the pronunciation; 
but the name, in a majority of cases, is really expressive, — giving 
both origin and insertion. An example of this double office of the 
name, may be noticed in stylo-glossus — meaning that it arises from 
the styloid process, and is inserted into the tongue. In hyo-glossus, 
the same advantage occurs : it simply informs us that it arises from 
the hyoideus, the bone of the tongue, and is inserted into the tongue. 
The muscles of the thigh and leg, are particularly vexatious, in this 
respect, to a young beginner. However, by patiently exercising the 
mind, in a little time the system becomes familiar. 

Though one bone only is embraced by the muscles of the thigh, 
the circumference is vastly greater of this part of the limb, than the 
leg. This depends on the number and magnitude of the muscles, 
which pass over the femoris, from the pelvis, to reach the bones of 
the leg below the knee joint. All the muscles on the fore part of the 
thigh, come from the upper end of the bone, and the hip, or ilium, 
and instead of being at all devoted to the service of the bone over 
whose surface they run, they are all concentrated in the knee pan, and 
therefore belong to the leg, as its extensors or straighteners. So 
violently have they been known to contract, that they have actually 
broken the knee pan into two pieces, — one half held by its ligament, 
down to its place, but the other, drawn by the uncontroled energy 
of the muscles, several inches up the thigh. When rising from a sitting 
posture, the entire weight of the bodj^ is raised by these same muscles; 
but they would be inadequate to the task, were it not for the sliding 
of the knee pan up the thigh, thereby increasing the power, by re- 
moving the fulcrum from the centre of motion, till the body is erect, 
when it slips into a pit, made by the meeting of the ends of the thigh 
and leg bones. While sitting, the muscles being at rest, the knee pan 
falls mto the space between the ends of the bones, made by bending 
the limb. It is on this principle that the sessamoid bones are thrown 
in under the tendons of the toes, to increase the power of the flexor, 
by removing the centre of motion further from the joint. This is a 
plan of nature's to protect the toe^ which, being over worked, would 
be ruined, were not an immediate provision made for increasing its 
power to meet the exigency of the case. 



Inserted into Use, 

The upper and back part of To bend the leg. 

the tibia, forming the outer 

hamstring. 

The upper and inner part of To assist in bending the 



the tibia. leg 

9# 



102 



ANATOMICAL CLASS BOOK. 




MUSCLES SITUATF^D 0.\ THE LEG. 

JVam e . Jlrises from 

Gastrocnemius externus, or The internal and external 
Gemellus. condyle of the femur. 



ANATOMICAL CLASS BOOK. 103 



Explanations of Fig. 46. 

a. Tensor vaginae femoris. 

b. Sartorius reflected. 

c. Rectus reflected. 

d. Vastus externus. 

e. Vastus internus, pulled outward. 
/. Pectinalis reflected. 

g. Adductor longus reflected. 

h. Adductor magnus. 

i. Gracilis. 

k. Ilracus internus. 

I. The anterior crural nerve. 

m. The femoral artery. 

5. The aiteria profunda. 

6. The external circumflex artery. 

7. The internal circumflex artery. 
71. The femoral vein. 

0. The cruralis. 

p. The adductor hrevis. 

q. The obturator artery and nerve. 

o. The cruralis, vel crureus. 

p. The adductor brevis. 

Vt'ere it not for the tendons of the vast number of muscles which 
slide by the knee joint, as remarked in speaking of the anatomy of the 
bones, this would have been- an imperfect articulation. Behind, the 
hamstrings contribute, on either side, to the formation of a canal, in 
which the artery, vein and great nerve of the leg, carefully cushioned 
up in a quantity of fat, lie so securely, that they very rarely come to 
any injury. One object of introducing Fig. 45, opposite, was to 
show the general relation of some of the blood vessels, — the nerve 
that suppUes the fore part of the thigh, and to exhibit the muscles 
already shown in a preceding figure, differently displayed, which 
have such a bearing on the anatomy of the joint. Several of the 
long ones are divided, in order to give a clearer view of those which 
would otherwise be too much hidden, to be understood^ The sarto- 
rius or tailor's muscle, so called because it crosses the legs, is marked 
c — the upper portion being taken away to show i, the gracilis. 
In nearly all operations on the artery of the thigh, the surgeon is 
guided by the edge of the sartorius — a sure index ; it also contrib- 
utes to the lateral security af the knee. 



MUSCLES SITUATED ON THE LEG. 

Inserted into Use. 

The OS calcis, with the To extend the foot, 
tendon of the soleus. 



104 



ANATOMICAL CLASS BOOK. 



An: me. Arises from 

Gastrocnemius internus, or The head of the fibula, and 

back part of the head of the 

tibia. 
Plantaris. The outer condyle of the os 

femoris and capsular ligament. 



Soleus. 



Fig. 47. 



Fig. 48. 




ANATOMICAL CLASS BOOK. 105 

Inserted into Use. 

The OS calcis, by a common To extend the foot, 
tendon, which is called tendo 
Jlchilis, 

The OS calcis, near the To assist in extending the 
tendo Achilis. foot. 

Explanations of Fig. 47. 
h. The tibialis anticus. 
i. The extensor longus digitorum. 
k. The peroneus tertius. 
I. The extensor longus, or proprius pollicis. 
m. The extensor digitorum brevis. 
71, The pe rone us longus. 
o. The peioneus brevis. 
p. The annular ligament. 



' Explanations of Fig. 4S. 
h. The tibialis amicus. 
i. The extensor longus digitorum. 
I. The extensor longus pollicis. 
q. The anterior tibial artery. 
r. The anterior tibial nerve. 



A similar provision is made in the leg for keeping the muscles 
down to their proper places, that has been noticed in the fore arm. 
Those bands, called annular ligaments, which encircle the ankle, to 
prevent the tendons, as they run upon the top of the instep, from 
flying out from the bones, in a high state of contraction, must excite 
atlmiration. This they have a constant tendency to do. If a 
person is walking up a flight of stairs on his toes, he will then per- 
ceive the strong action of the tendons, and the reaction of the liga- 
ments upon them. All those animals which climb, as squirrels, 
monkeys, bears, and gome others, have the fascia or limb cases, 
much thicker, in proportion to the size of the body, than in man. 
All the tendons of the toes and fingers are bound down to the bones 
by inelastic bands, — in a similar manner. Birds, particularly those 
that roost, have a beautiful web of ligamentary threads woundround 
the leg, just above the toes, for restraining the tendons. 

Fig. 46, displays an intricate mass of muscles, originating between 
the upper extremities of the leg bones. For nearly a foot below the 
knee, it is dilflcult to designate one from the other, on account of the 
intermingling of the fibres. However, the tendonsof each, are distinct. 
No important vessels or nerves are exposed on the skin : — on the 
opposite side, however, they are to be found, safely protected by 
muscles, bones and fascia. 



106 



ANATOMICAL CLASS BOOK. 



JSTame, 
Tibialis anticus. 

Tibialis posticus. 



Fiz. 49. 




Arises from 

The upper and fore part of 
the tibia. 

The back part of the tibia, 
interosseous ligament, and ad- 
jacent part of the fibula. 

Fig. 50. 




ANATOMICAL CLASS BOOK. 107 

Inserted into Use, 

The OS cuneiforme inter- To bend the foot. 

num. 

The middle cuneiform bone, To move the foot inward. 

and upper part of the os navi- 

culare. 

Explanations of Fig. 49. 
q. The plantaris. 
r. The popliteus. 
s. The soleus. 

t. The biceps, forming the outer hamstring. 
u. u. The seniitendinosus and semimembranosus, forming the in- 
ner hamstring. 



About the knee and ankle joints, professional bone-setters have 
played, and are still playing, a high handed game of quackery and 
imposition. On that account, therefore, it has been an important 
object, to embody as much general information, in relation to the 
anatomy of the lower limbsj as possible, and at the same time avoid 
writing a professional essay on the diseases and incidents to which 
they are particularly predisposed. Three bones, only, enter into the 
composition of the knee joint; yet in this land of common sense, indi- 
viduals injure the articulation, and have it made well, by the reduc- 
tion of six or seven ! The ankle joint, made up entirely of three 
bones. — is often cured by having several little hones thrust into 
place ! 

In the immediate neighborhood of these joints, a multitude of 
tendons have been seen, in the preceding diagrams, on which their 
perfection depends. By a thousand accidents to which they are ex- 
posed, the tendon of a particular muscle may be so prodigiously 
strained as finally to become inflamed. No pain is more severe nor more 
tedious in point of duration, than sprains — or over stretching of the 
tendons and ligaments. Though slow to feel, — when once roused, 
they are as ditiicult to manage as the bones, because they possess a 
vitality so low and so far removed from the sensibility of the soft 
parts, that remedies are a long time in effecting a restoration. To an 
inflammation therefore, and not to the out-of-joint condition of the httle 
bones, is to be imputed the cause of protracted lameness in a majority 
of cases. The metatarsal bones of the instep are not thrown out of 
place once in a hundred instances where it is supposed they are. 
To youth, these remarks are addressed. 



108 



ANATOMICAL CLASS BOOK. 



JSPame, 
Peroneus longus. 

Peroneus brevis. 

Extensor longus digitorum 
pedis. 

Extensor proprius pollicis 
pedis. 

Flexor longus digitorum 
pedis, profundus, persorans. 



Arises from 

The head of the tibia, and 
upper and outer part of the 
fibula. 

The outer and fore part of 
the fibula. 

The upper part of the tibia, 
interosseous ligament, and in- 
ner edge of the fibula. 

The upper and fore part of 
the tibia. 

The upper and inner part 
of the tibia. 



Flexor longus pollicis pedis. A little below the head of 

the fibula. 



Fig. 51. 




Explanations of Fig, 51. 

f The external plantar artery, 

g. The interiial plantar. 

h. The tendon of the flexor longus pol- 
licis. 

i. The tendons of the flexor longus 
* digitorum. 

i j. j. The massa cainea JacoLi Sylvii. 
i k. k. k. The lunibricales. 



MUSCLES CHIEFLY SITUATEir ON THE FOOT. 

Extensor brevis digitorum The upper and anterior part 
pedis. of the os calcis. 

Flexor brevis digitorum pe- The lower part of the os 
dis, perforatus sublimis. calcis. 



ANATOMICAL CLASS BOOK. 



109 



Inserted into 
The metatarsal bone of the 
great toe. 

The metatarsal bone of the 
little toe. 

The first joint of the small 
toes by the four tendons. 

The convex surface of the 
bones of the great toe. 

The last bones of all the 
toes, except the great toe, by- 
four tendons. 

The last bone of the great 
toe. 



Use, 
To move the foot outward. 



To assist the peroneous 
longus. 

To extend the toes, and 
separate them from one ano- 
ther. 

To extend the great toe. 

To bend the last joint of 
the toes. 

To bend the great toe. 



Notwithstanding the multitude of bands, muscles, cords and ves- 
sels, were it not for the broad sheet in the sole of the foot, reaching 
from the heel to the roots of the toes, like the sole of a shoe, all the 
parts we have been considering would have been inadequate to its 
security. The plantaris, the name of this ligament, binds the arch 
of the foot, and effectually prevents the bones from being spread 
apart, and at the same time constitutes a firm external defence for 
the muscles, nerves and vessels. A similar broad ligament exists in 
the palm of the hand, for the same purpose. 



MUSCLES CHIEFLY SITUATED ON THE FOOT. 



The first bone of the great 
and other toes, except the 
little. 

The second phalanx of each 
of the small toes, by four ten- 
dons, w^hich are perforated by 
those of the flex. long. dig. 
ped. 



To extend the toes. 



To bend the second joint of 

the toes. 



10 



no 



ANATOMICAL CLASS BOOK. 



Lunibricales pedis. 

Flexor brevis poUicis pedis. 



Abductor polJicis pedis. 
Abductor pollicis pedis. 

Abductor minimi digiti pe- 
dis. 

Flexor brevis minimi digiti 
pedis. 

Transversales pedis. 

Interossei pedis interni. ^ 

Interossei pedis externi. ) 



Arises from 

The tendons of the flexor 
longus digitorum pedis. 

The fore part of the os cal- 
cis, and external cuneiform 
bone. 

The inner and lower part 
of the OS calcis. 

The ligament extended from 
the OS calcis to the os cuboi- 
des. 

The tuber of the os calcis, 
and metatarsal bone of the 
little toe. 

The root of the metatarsal 
bone of the little toe. 

The ligament connecting 
the bones of the tarsus. 

The metatarsal bones. 




Explanations of Fig. 52. 
/. The plantar arch, 
m. The tlexor brevis pollicis. 
n. The adductor poUicis. 

The flexor brevis minimi digiti. 

The transversalis pedis. 

The interossei. 

The long ligament of the calcis. 

The tendon of the peroneus longus. 



ANATOMICAL CLASS BOOK. 



Ill 



Inserted into 

The tendinous expansion at 
the upper part of the toes. 

The first joint of the great 
toe, by two tendons. 

The first joint of the great 



Use. 

To draw the toes inward. 

To bend the first joint of 
the great toe. 

To move the great toe from 
toe. the rest. 

The outer sesamoid bone, To draw the great toe 
or first joint of the great toe. nearer to the rest, and to 

bend it. 

To draw the little toe out- 
ward. 



The first joint of the little 
toe externally. 

The root of the first bone of 
the little toe. 

The tendon of the adductor 
pollicis. 

The metatarsal bones.. 



To bend the little toe. 

To contract the foot. 

To draw the smaller toes 

towards the great toe, and 

, assist in extending the toes. 



112 ANATOMICAL CLASS BOOK. 



QUESTIONS 



Where are the ligaments found ? 

What is Syndesmology'^ 

Have the ligaments sensibility ? 

Are they elastic ? 

Are there ligaments within the skull ? 

What prevents tha bones of the foot from separating, when 

we stand ? 
What do you understand by Myology. 
What is a muscle? 

What are the characteristics of a muscle. 
Their use ? 

What makes them red ? 
Have they nerves ? 
Are they all of the same figure ? 
How do muscles act ? 
How are muscles divided? 
Where are the involuntary muscles found ? 
Why does it require practice to play musical instruments ? 
Have the muscles a vitality which survives the death of the 

nerves ? 
Has each muscle an antagonist ? 
Are they ever relaxed? 
Do they ever become weary ? 
What is contractility, as applied to the muscle ? 
What are tendons ? 



ANATOMICAL CLASS BOOK. 113 

Where are they found ? 

In cases of suspended animation, through the agency of 

what organs is vitality recalled ? 
How many muscles are there ? 
Are muscles always in pairs ? 

How many muscles from the elbow to the fingers ? 
What muscle raises the whole arm to a horizontal posture ? 
What muscle surrounds the eye, within the eyelids ? 
Has the nose any muscles ? 

Are there muscles connected with the external ear ? 
What muscles bend the head forward, as in bowing? 
What muscles assist us in walking ? 
What muscles are in action, in sounding the vowels ? 
What muscles sustain the upright position of the back ? 
What muscles extend the fore finger? 
What muscle bends the fore arm on the arm ? 
What is the fascia and its use ? 
What muscle is the longest in man ? 
Are there muscles in the tongue ? 
Do muscles have any agency in modulating the tones of the 

voice ? 
By how many muscles is the eye moved in its socket ? 
What muscle rolls the eye downward, towards the shoulder ? 
What muscle lies over the back of the neck, like a tippet ? |j 

What muscle extends the whole forearm? 
What muscle rolls the fore arm to and fro ? 

What muscles constitute the calf of the leg? | 

Where do the flexors of the toes run, to reach them ? "| 

What muscle enables us to blow with the mouth? I 



10* 






114 ANATOMICAL CLASS BOOK. 



APPARATUS OF JOINTS 



OR BURSOLOGY. 



Within the joints or in their immediate vicinity, there 
are small sacs, containing a glairy, oily fluid, which is 
poured out between the articulating surfaces, to prevent 
friction ; the name of this substance is synovia. Upon the 
same principle that any machinery is kept oiled, the joints 
are lubricated. When the secretion of the synovia, is im- 
perfect, or scantily effused into the joint, the highly polish- 
ed surfaces of the cartilages become rough, dry and sub- 
sequently inflamed. 

Even in the sheaths of the tendons, these oil bags are 
considerably numerous. A bout the wrist, elbow, shoulder, 
hip, knees, and ankle, they are large, but of various 
shapes, according to the space afforded them. Where the 
most motion is required, there are the largest sacs, secret- 
ing and throwing into the place, a copious quantity of 
the oil. A disease of the hursce mucoscs, which is the 
scientific name of the sacs, is familiarly known as the 
white swelling^ — particularly of the hip and knee. 

It would not be profitable in a simple elementary trea- 
tise to dwell minutely on this subject. The ^ew observa- 
tions here made, will satisfy the inquirer, that the care 
which is everywhere displayed in animal mechanism, de- 
monstrates in the most happy and unobjectionable man- 
ner, the contrivance of a Being antecedent and superior 
to ourselves. 



ANATOMICAL CLASS BOOK. 115 



FLUIDS, OR ANGIOLOGY. 



THE HEART AND CIRCULATION OF THE BLOOD. 

It is one of the most curious facts in the whole range of 
physiological science, that the ani^ients were totally igno- 
rant of the circulation of the blood. 

By a long course of observations, it was commonly ad- 
mitted that there were in man, for example, two sets of 
tubes, which coursed through the body, and they assigned 
to each many absurd and ridiculous functions. 

As one set of vessels w^ere superficial, directly under the 
skin, filled with the venous bloody which quietly moved 
along the smooth duct, — from some unknown point, to 
another, equally obscure, they were fully satisfied that it 
belonged, in some way, to the body. On the other hand, 
by various accidents, they had frequent opportunities of 
viewing the deeper seated vessels, throbbing and getting 
blood in recent wounds : — but as the color of their con- 
tents was different from that in the veins, and the activity 
that was manifested by these tubes, when exposed to their 
astonished vision, altogether different from the motionless, 
well behaved veins, the idea was at once admitted that 
these, which were denominated arteries, constituted the 
laboratory of the animal spirits, — or, in other words, it 
was in the arteries that the powers of the soul were gene- 
rated, in combination with atmospheric air, which found 
its way into the reservoirs of life, through the pufiing and 
blowing exercises of the lungs. When the artery was cut, 



116 ANATOMICAL CLASS BOOK. ' 

and the warm blood was forced out by strong pulsations, 
then the spirit within was angry, — and so vented its 
displeasure and spite, like a snarling child, by spirting 
out its own precious self through the incidental aperture. 

Upon notions as rational as these, learned men con- 
structed some of the strangest theories that ever beset the 
imagination. When the whole subject of the use of the 
arteries and veins were supposed to be clearly understood, 
those sage investigators of the sublime and beautiful, 
rested from the weight of their labors, and, subsequently, 
established certain doctrines, which held a despotic sway 
for centuries ; yet they were as far from truth, as possible, 
— and worse than all, ho person of common sense dared 
to call them in question. 

Who but a blockhead would ever have entertained a 
notion like this, viz. that the blood ran out from the h^art 
through the day, or while one was awake, and returned 
again at night, when the individual retired to his slumbers ! 
Who but a profound dunce would have suggested the novel 
theory that weariness, the sensation of hdng tired, was in 
consequence of being so long awake, that the blood had 
all run out from the fountain head : — and when one could 
not move any longer, from complete exhaustion, why nature 
indicated at once what was to be done : — only lay the 
poor sufferer on a bed, the recumbent posture being 
highly favorable, the blood immediately took a dovvnhil 
direction, and when it had all reached home, and was 
snugly settled down in one of the chambers of the heart, 
the tendency to death was suspended, — the man recov- 
ered his accustomed strength, and bright and early the 
next morning the sanie truant blood was ready to travel 
over the old ground again ! 

Thus it will be plainly under^tood, that the arteries were 
expressly set apart as a habitation for the spirit or vital 
principle : the veins, because they w^ere less noble, were 



ANATOMICAL CLASS BOOK. 1 17 

on the outside, while the others within, were exclusively 
appropriated to the to and fro, night and morning cir- 
culation of the blood. 

Another discovery, equally surprising, and in exact 
keeping with the foregoing arrangement, related to the 
heart. They saw a little thing carefully boxed up in the 
chest, between the right and left lung, which to all intents 
and purposes satisfied the student of nature, that it was 
very Jiot, or it would not have been confined and sur- 
rounded by two great bags of wind : — it was kept tolera- 
bly cool by constant respiration ! 

The heart being decidedly a hot affair, there was a grand 
field for exclaiming and proclaiming the wisdom of nature, 
in providing such a delicate and at the same time simple, 
but perfect contrivance for keeping down its temperature 
below the boiling point ! It was laced up in a straight 
jacket, — the pericardium, vulgarly called heart-case, of a 
texture so firm, that it was as self-evident as that the earth 
was the centre of the solar system, that this organ was liable 
to prodigious paroxysms of rage, and would burst from its 
prison, were it not thus secured. Two points were thus 
satisfactorily settled : viz. that it was very hot, and very 
unruly. 

Again, — within, there were certain apartments, which 
took the sensible and significant names of auricles and 
ventricles, — because the walls of the one bore some fanci- 
ful resemblance to the ears of a dog — but which, by the 
way, bear just as much resemblance to the horns of the 
new moon ; and in these cavities certain curious opera- 
tions were going on, which none but very wise philoso- 
phers understood. These consisted in the mixing of air 
and blood, — the instantaneous development of certain 
matters and things which constituted life, and gun-powder 
like explosions, consequent upon the ingress of cold air in 
the furnace of the heart. 



118 ANATOMICAL CLASS BOOK, 

In reality,. had those investigating geniuses of the olden 
time, whom it is so fashionable to admire, so classical to 
praise, known anything of the modern properties of the 
steam-engine, it is altogether probable they would have 
had much to say on the heart's property of generating 
power by converting its liquid contents into vapor, and, 
in the sequel, laboriously explained the causes which oc- 
casionally oppressed, — which clogged the wheels of vital 
action, and which, in plainer language, sometimes burst 
the boiler. 

We have merely sketched an outline of the general 
views which were entertained of the physiology of the sys- 
tem by the ancients ; — views it would seem, so absurd that 
the reflections of a school-boy would have overturned them : 
yet, strange as it now appears, they were carefully trans- 
mitted from one generation to another, for many centuries, 
and treasured up as the profound discoveries of antiquity. 

THE HEART. 

It would seem, at first view, from the high office of the 
heart, so constantly found in all animals with which we 
are familiar, that no organized being could possibly exist 
without it. Strange, however, as it may appear, there 
are various classes, in the lowest orders of animal crea- 
tion, which are totally destitute of it ; still, they have blood, 
and that can under no circumstances be dispensed with, — 
but is not propelled by one single organ through the ves- 
sels. There is a compensation, however, in the structure 
of the primitive vessels, — or to be understood, a blood- 
vessel takes upon itself all the functions of a heart, ex- 
erting by successive pulsations, a power adequate to the 
physical requirements of the body in which it is found. 

Numerous, indeed, are the insects and vermin, in 



ANATOMICAL CLASS BOOK. 



119 



which this kind of organization is discoverable. But it 
is not an organization favorable to longevity, for those in 
which this simple apparatus exists, are the beings only of 
a day; they flit in the sunshine a few hours; the object 
of their creation is attained, and they die. 

A resemblance to this sort of machinery is noticed in 
fishes; though they have a heart, it is exceedingly imper- 
fect, when compared to the same organ in warm-blooded 
animals. 

Fig. 53. 




Explanation of Fig. 53. 

A. j1. are the fringes of the gills, attached to half hoops of cartil- 
a2;e. These threads, which are of a bright red, are the extreme 
terminations of the branchial arteries ; in an animal breathino air, — 
the same vessels are called bronchial arteries. 

B. the ventricle of the heart, or forcing-pump, which drives the 
blood with which it is distended, into a single artery. Just beyond 
B, the artery D divides into two branches, leading to the gills on 
either side, in equal quantities. Precisely like this, is the right 
heart of man. Instead of being thrown into gills, the branches di- 
rect the blood into the lungs. C, the auricle, or first receiving cav- 
ity of the heart. All the veins of the body in all animals, whether 
belonging to the land or water, ultimately unite into one tube, and 
tiiat empties its blood into the auricle. 

E. In this diagram, E is the branchial vein, of the right gill soon 
united to that from the left side The blood has been changed in the 
gills, where it was sent by the heart, by being brought in contact 
with the'air in the water, and now being fit for the purposes of the 
system, is returned by these veins, to a great vessel, lying under the 
backbone. 

F. This is the reservoir of the revitalized blood: — at its com- 
mencement in the gills, it is like a vein, — but the main trunk now 
assumes the functions of an artery, or indeed a second heart. It 
contracts and propels its contents over the body. Here then is a tube 
taking upon itself the office of the left heart of land-dwelling ani- 
mals. 



120 ANATOMICAL CLASS BOOK. 

Were it profitable, reference niight be made to very many curious 
modifications of tbis blood-piopelling apparatus, so positively neces- 
sary to the existence of all organized beings, in the oyster, cuttle- 
fish, birds, lizards, serpents, tortoises, frogs, tadpoles and some other 
reptiles. 

Indeed, the fish has but half a heart. All their blood, — 
and in some of the huge monsters of the ocean there is a 
prodigious quantity, — is sent its rounds by an artery^ and 
not by a heart or any particular part of one. Here we 
perceive that a force is exerted by the contractions of a 
single vessel, equal, (for it must be in sharks of thirty feet 
in length,) to a moderate sized fire-engine. We positive- 
ly know it to be so, because the blood, by each pulsation, 
is driven through as much space in a given time, as the 
water is thrown by the piston of the engine. 

In the mammalia, that is, animals breathing air, the 
heart is the centre of the circulation — the point from 
whence the blood starts, and the instrument of propulsion, 
by which it is kept going in an endless round, in the body. 
It is a forcing-pump, by which a column of fluid is raised, 
and an imitation of its mechanism may be examined in 
every house in which one of those convenient machines 
is used for filling tanks in the upper apartments. One is 
self-moving, having incorporated within its own substance, 
the wonderful power of generating physical strength ; while 
in the other, an extraneous force must be applied, some- 
where, to put it in motion. 

Surely the most sceptical must acknowledge in this in- 
stance, and it is only one of many millions which might 
be cited, that the work of an Almighty Being is here most 
certainly manifested. How simple the contrivance, yet 
how astonishing the results ! 

In warm-blooded animals, the heart is a compound en- 
gine. If we go back to tlie fishes it is there single ; but 
in man, quadrupeds and birds, it is double : they have two 
hearts, and both of them are forcing pump?. Man has 



ANATOMICAL CLASS BOOK. 



121 



two hearts^ but they occupy less room by being joined to- 
gether, though, for aught we can discover, the system 
could be just as well supported, had one of them been 
placed at one side of the chest, and the other at another 
part. By being united less substance is required ; sym- 
metry is preserved, and the union of the two actually con- 
duces to the greater muscular power of both. 

Fig. 54. 




Explanation of Fig. 54. ^ 

By this engraving, the reader will readil}' understand what we 
mean by the two hearts of man, and other warm-biooded animals, as 
they are here exhibited, and as they appear when dissected aparf. 
Each one of them is a perfect organ, by itself, and the one is per- 
fectly independent of the other. That having the letter h upon it, 
is the n^/ii heart, — and that with a g, the left. This is a front 
view, or like looking into the chest of another person. The right 
heart is the engine of the lungs, — for it supplies those organs ex- 
clusively. The left heart throws the blood, as already remarked in 
the text, round the curve above g, in the direction indicated by the 
arrows, over the entire body. 

a a are the cavas, or great veins, — returning blood from the 
head and arms, and lower extremities. The uppermost is the su- 
perior vena cava, and the one below, the inferior vena cava. The 
arrows show the direction of the returning currents of venous blood, 
to 6, the auricle, which forces it into c, the ventricle, which again 
forces it up into a, the pulmonary artery, where it divides, to go to 
each lung ; e, is one of Xho, four pulmonary veins, which convey the 
blood just forced into the lungs, into the auricle f, of the left heart. 
When that contracts, it drives its blood into g, the ventricle, which, 
in its turn, forces it onward again into the arch, or the aorta, the 

11 



122 ANATOMICAL CLASS BOOK. 

main pipe, where it glides along in the direction of the arrow, di- 
viding into smaller streams on its way, and finally goes down the 
descending aorta h, to supply the body below. 

There are many animals which have only the right heart, but 
none that possess the left one alone. The fishes heart, in the plan 
preceding this, is the single, equivalent to the right heart of man. 

That there might be no interference, no irregularity, 
but perfect order and harmony, only one acts at a time. 
The right heart rests while the left moves, and then, in 
perfect obedience to a law which cannot be explained, 
operates in its turn. 

In configuration, the heart has no such vulgar shape as 
we are told in some of the books, like the ace of hearts 
on a playing card. It is a short cone, lying obliquely 
across the breast, the point of which beats, when in an 
erect posture, between the sixth and seventh ribs of the 
left side. 

Within, there are four apartments, so irregularly shap- 
ed, that they cannot be likened to anything. Each heart 
has its two cavities, communicating with each other by 
an orifice, about an inch in diameter, but a complete valve 
is suspended on the margin of the opening, like a gate, 
to close it, that all communication may be instantaneously 
interrupted, as we shall ascertain to be indispensably 
necessary, at each pulsation. Moreover, to prevent the 
heart from ever being over distended, from having its walls 
put too much upon a stretch, little cords of astonishing 
tenacity, run from one side to the other crossing and re- 
crossing each other in all directions, which also assist, by 
contracting, to squeeze it, as it were, together, in forcing 
out its contents. 

To secure it still farther, guarding against all contin- 
gencies, the heart is enveloped in a tough, slightly elastic 
case. Having this support, were the internal straps to be 
rent from their attachments, the swelling heart would be 
met from without, by its covering, and prevented from 
being ruptured by the accumulation of the blood within. 



ANATOMICAL CLASS BOOK. 123 

liastly, that the freedom of motion might never be 
abridged, the heart is suspended at the top of the chest, by 
its own tubes, being at liberty to swing in the triangular 
space given it between the lobes of the lungs, according 
to the various attitudes the body assumes. This is not 
all ; the heart constitutes a hollow muscle, being as com- 
pletely flesh as the muscles of the arm. Besides, it pos- 
sesses all the essential characteristics of every muscle, the 
inherent property of contractility. 

Having explained the fact that there are two hearts, it 
is now necessary to show the necessity of this arrange- 
ment, which is no easy matter, inasmuch as we are to 
adapt our demonstration to the capacity of the young. 

Throughout the system there are two sets of tubes for 
conveying blood ; — one conducting it through the body, 
and the other returning it. To be serviceable to the 
system, which is the final cause of the elaborate machi- 
nery under consideration, two other important organs must 
necessarily claim attention, viz. the stomach and the 
lungs. 

In the former, the food is converted into a milky liquor, 
from, whence it is actually conveyed into one of the cavi- 
ties of the heart ; but before it can be of any service, it 
must first be mixed with that already in the veins. A 
chemical change is effected in it by being exposed to the 
action of the atmospheric air, that makes it blood. 

As the first process is completed, the next object nature 
has in view, is to distribute it, and the left heart is the 
apparatus by which it is effected. There is no communi- 
cation between the cavities of the two hearts, but we per- 
ceive that the blood which is pouring into the right side, 
must be thrown somewhere, and as it cannot go into the 
left, where, the query will arise, does it move ? — directly 
into the lungs. From thence it is collected, and by four 
branching tubes carried to the left heart. Thus, the left 



124 ANATOMICAL CLASS BOOK. 

heart forces it in all directions from the centre, and the 
right heart forces that which has been returned into the 
lungs. 

By an untiring labor of the two hearts, acting alter- 
nately, from birth till death, the blood, that important sub- 
stance, on which life depends, is kept always going and 
coming, and whatever property or quantity is lost on the 
route, is supplied by the activity of the stomach, the great 
laboratory in which the material is manufactured of which 
it is originally made. 

Authors detail the particulars of what they call the 
two circulations, — viz. the greater and lesser, by which is 
to be understood, that the right heart and lungs constitute 
this lesser, because the force of the engine is only exerted 
to throw its contents into the air cells of the lungs. On 
the other hand, the greater circulation, means the left 
heart and all the arteries leading from it, quite to the ex- 
tremities. 

As the power to be exerted by the left heart, in order 
to throw the blood the entire length of the body, is vastly 
superior to its fellow, which is only required to push its 
volume of blood about ten inches, so it is proportionably 
stronger in its substance ; thicker in its walls, and more 
sensitive to the application of stimuli. In the act of dying, 
the left heart invariably clears all its cavities, — and there- 
fore is always empty on dissection, but the right heart re- 
mains full and burthened. 



ANATOMICAL CLASS BOOK. 



125 




Explanation of Fig. 55. 

The double heart of man ; — q, descending vena cava ; o, ascend- 
ing vena cava ; n, right auricle ; b, right ventricle ; k, pulmonary 
artery; 1,1, right dind left branches of this artery, going to the 
lungs on either side of the chest ; m, ?n, veins of the lungs, which 
return what the artery sent in, to r, the left auricle; a, the left ven- 
tricle ; c, e,f, aorta or great artery of the body, rising out of the left 
heart; g, arteria innominata ; h, the subclavian artery , going to the 
left arm ; i, the carotid artery, which goes up the side of the neck 
to the head. JVote — the arrows show the course the blood moves 
in each of the vessels demonstrated with the heart; n, right auricle; 
m^ m, veins of the lungs ; s, left coronary artery. P, veins returning 
blood from the liver and bowels. 

There is' no essential difference in the external appearance, or in- 
ternal organization of the heart of man, and breathing animals gen- 
erally ; hence, in a cabinet, it would be exceedingly difficult for a 
practical anatomist to designate the human, from the heart of a brute, 
provided they were of equal dimensions. 

Nothing is easier, than to fill a heart with wax, or even plaster 
paris, in order to exhibit, distinctly, all its vessels and its exact shape 
in a state of distention. The heart of any of the domestic animals, 
procured at the market may be thus, filled, and kept for many years, 

XI* 



126 ANATOMICAL CLASS BOOK. 

Ultimum moriens, the last part to die, was an accurate 
remark of the old anatomists. In reptiles and fishes s^ 
irritable is the heart, — and it is to be remembered, they 
possess only one half of ours, equivalent to the left one, — 
that long after the body is dead, the heart, separated from 
all its connexions, will continue to pulsate upon the table 
for half an hour ; — when it has exhausted itself, if it be 
touched with the point of a pin, it will be roused into ac- 
tivity again, and beat and throb as though it were con- 
scious of making a desperate struggle for existence. 

When the frog's heart has been a whole hour under in- 
spection, it will continue to pulsate, even by blowing it. 
The mangled body, all this time disemboweled, shocking 
as it may seem, leaps about the house, without a heart, 
without blood, and with lacerated nerves and muscles, 
apparently just as well as before those cruelties were com- 
menced. 

Each heart has two cavities, as repeatedly remarked, — 
but for the sake of conforming to the usual method of de- 
scription we will say, the heart has four cavities, two of 
which are the auricles, being uppermost, and two directly 
beneath them, the ventricles. 

The numerous threads, already spoken of, reaching 
from one side to the other, are called cordcD tendinecB, and 
those which are fleshy in the middle columnar and massce 
carnecB. Their office is merely to prevent the auricle from 
being overcharged, — acting precisely upon the principle 
of a tape the manufacturer tacks in to keep the lid of a 
trunk from falling open so far as to wrench off the hinges. 

From the lower part of the auricle, the opening into the 
ventricle is a smooth round hole, opened and closed by a 
valve that springs downward, but never, in any instance on 
record, has it been pushed up through. The valve is curi- 
ously supported by little tags, lines and weights to prevent 
its being pressed by any force that might have a tendency 



ANATOMICAL CLASS BOOK. 127 

to press it the wrong way, — and at the same time, these 
accompaniments assist m moulding the edges precisely to 
the ragged surface of the border of the hole, so that it 
shall be completely tight. That it is impervious, may be 
inferred from the fact, that the heart has been repeatedly 
ruptured by its own exertion, on the blood filling its ventri- 
cles, or auricles, yet the strong walls, half an inch in 
thicknesss, gave way, while the tiny, transparent valve, 
maintained its place. 

The strips which enter into its composition, being fanci- 
fully imagined to be three, takes the name of tricusped^ 
because it has three points supposed to resemble teeth. 
On the top of the auricle, two or three large veins pre- 
sent their mouths : — one is the vena cava superior^ the 
great trunk which brings all the blood from the head and 
arms into the reservoir ; and another, nearly opposite, is 
the vena cava inferior^ in which all the blood is brought 
from the feet and body. There is a third, very much 
smaller, however, the coronary vein, returning the blood 
which has circulated exclusively in the substance of the 
heart. Over this last opening, is a crescent shaped valve, 
highly important, for were it not there, every time the 
auricle contracted, it would force the blood wherever there 
was no resistance, which therefore, instead of allowino- the 
venous blood to return into the common fountain, would 
be continually driven onward, so that the heart itself would 
suffer from an obstructed circulation : this half moon 
shaped valve, swinging downward, entirely opposes the 
ingress of blood from the auricle, yet freely allows that 
coming from the heart to make its exit by the valve. 

Can we contemplate anything more purely mechanical 
than this contrivance. Can any one in his senses argue 
himself into the absurd belief, that this peculiar arrange- 
ment, this striking adaptation of parts, all concurrino-tothe 



128 ANATOMICAL CLASS BOOK. 

Utmost perfectablility of the machine, splendid in its struc- 
ture happened all hy chance ! 

The auricle being filled, — the sense of fulness, a pro- 
perty entirely independent of the mind, wholly beyond the 
control of the laws of volition, prompts it to expel it. This 
it does by collapsing ; by simultaneously contracting all 
its parts upon the mass within, which is thereby driven 
per saltum, through the great canal, down into the ventri- 
cle, — the second apartment. To admit it there, a pre- 
paration is necessary on the part of the ventricle, — and 
that consists in relaxing itself to enlarge its capacity for 
receivincT the portion that is on the way from the auricle. 
At the instant of being filled, the tricusped valve, which 
was before pendulous, flaps back, cuts off all further com- 
munication, and thus holds all that has been admitted, to 
be afterwards disposed of 

Because the auricle is obliged to make an effort only 
strong enough to urge its contents by the valve, it is com- 
paratively slightly made, and weaker than the ventricle. 

Having the ventricle filled, let us watch the process by 
which it clears itself It has been premised, that its duty 
is to push the blood to the lungs, a distance of about ten 
inches, though if we suppose that the extreme ramifica- 
tions of the bronchial arteries are gorged by each throw 
of the ventricle, the power is equal to projecting the 
stream between seventy and eighty feet. This point is 
rather dubious; anatomists have not satisfied themselves 
whether the ventricle actually presses the blood to the ex- 
treme twigs of the lungs, or only sends it beyond the 
valves in the mouth of the pulmonary artery, hardly a dis- 
tance of seven inches. Be that as it may, the fact is no- 
torious, — if it were not designed to exert a force more 
than ten times as great as the auricle, surely it would not 
have been made so very much stronger, and so amply pro- 
vided with materials for that purpose. 



ANATOMICAL CLASS BOOK 129 

If the auricle can send a column of blood ten feet, the 
ventricle, by its additional physical advantages, could 
throw the same quantity fifty feet in precisely the same 
time. This looks a little like being able to reach the 
lungs, notwithstanding the reasonings of authors to the 
contrary. Suffice it, that when the stimulus of distention 
creates the exciting sensation, the walls contract, as in 
the other case, and every drop of the blood goes through 
a very delicately smooth, round hole, — the only outlet 
from the ventricle, besides the place of entrance, — and 
this is the beginning of the 'pulmonary artery^ the great 
blood vessel of the lungs. Here we leave the description 
of the right heart, for the present, lest minuter details 
should distract, rather than enlighten those who may, per- 
haps, endeavor to obtain their first accurate notions of this 
local piece of anatomy, from our dissertation. 

Much as the heart of the body, that on the left side, re- 
sembles the one before us, there are peculiarities requiring 
a careful and patient investigation, if we are desirous of 
perfectly comprehending its structure and interesting 
functions. 

Were a well prepared specimen of the heart to be lying 
before the reader, he would regard the general appearance 
of strength in the left side, as though more depended upon 
it in the economy of life, than on its associate. Such 
is truly the fact, that the power manifested by it, is im- 
mensely superior. 

United, as just seen, are the left auricle and ventricle, 
with a similar valvular communication between them. 
The left auricle is considerably larger than the right, but 
bears more resemblance to a square box, in a state of dis- 
tention, than a sac. The entire office of this is to expel 
the blood forcibly into its neighboring ventricle. Uniting 
by degrees, all the veins gradually terminate in four con- 
siderable trunks, in the two sides of the auricle, nearly 



130 ANATOMICAL CLASS BOOK. 

opposite to each other. Two of them bring the blood 
from the right, and the others from the left lobes of the 
lungs. 

When the ventricle is full, let it be recollected that it 
must send its blood in two directions, viz., towards the 
head, as well as the feet ; and at the same time, supply all 
the intermediate viscera, muscles, nerves, and even the 
very bones themselves, however hard or remote from the 
centre of the circulation. Whether the ventricle accom- 
plishes the feat, remains to be discussed hereafter. By its 
contraction, a valve called the mitral, shuts back to pre- 
vent a regurgitation, — hence the blood can only escape 
through the canal provided for it. This is a long, strong 
tube, nearly an inch in diameter, in man, known as the 
aorta. Directly in the calibre of the aorta are three valves, 
so adjusted to the condition and shape of the artery, that 
the three, in being spread horizontally, (the posture has 
no influence on the action) they effectually close the chan- 
nel, so that nothing which may have passed the portals, 
can possibly be returned. Thus the functions of the two 
hearts are analogous ; the principle of propulsion is the 
same, and indeed, when the office and organization of one 
is understood, it illustrates sufficiently well, the other. 

The line of union between the two, is termed the sep- 
turn cordis. All the fibres of the two ventricles have a 
v/inding direction, which give the heart a twisting or ver- 
micular kind of motion in its pulsations. The alternate- 
ly swelling and collapsing, as when full, or empty, are, the 
disastole and systole, terms used to express the pulsations. 

Although the heart is the fountain of life, dispensing 
the blood either directly, or indirectly, to the smallest twig, 
wherever located, in the body, it requires a circulation of 
the same vitalizing fluid, to sustain its own existence. 

For this purpose there are vessels creeping out at the 
sides of the aorta, at right angles with the trunk, just 



ANATOMICAL CLASS BOOK. 131 

above the semi-lunar valves, which wend their way direct- 
ly to the divisional horizontal line, between the auri- 
cles and ventricles, where, carefully imbedded in a trian- 
gular depression, out of the way, the coronary arteries 
are continually sending off branches that dip down into 
the substance of the heart, supplying it abundantly with 
arterial blood. When it has completed its route, and is 
in readiness to go on again, to get within the cavities of 
the heart, from the extremities of the coronary arteries, 
veins commence, called coronary, which keep gradually 
uniting, and ultimately coalesce in one single tube, the 
coronary vein, the diameter of a writing pen, whose mouth 
was found, on examination of the right auricle, be- 
hind a beautiful little coronary valve. In this way the 
substance of the heart is supplied with nutriment, to sus- 
tain it in a course of activity, that never tires, and which 
never ceases to palpitate, till death puts a stop to its 
motion. 

NERVES OF THE HEART. 

These are few, arising from the sympathetic and eighth 
pair of nerves. The sy?npathetic, is a kind of line of union 
receiving a deputation from all the principal nerves 
throughout the frame, by which a connexion is maintained 
with all the different parts of the complicated whole. 
The eighth pair of nerves arise in the brain, but traverse 
down the side of the neck into the chest, following the 
course of the windpipe and sesophagus, quite to the stom- 
ach. From these, there being a pair, one on either side, fil- 
aments shoot off to the heart. The minutce of the course 
is not essential. In this way the heart holds a line of 
communication with the work-shop, the stomach, where 
it looks for the manufacture of the material from which 
the blood is elaborated ; and by the other set of nervous 



132 ANATOMICAL CLASS BOOK. 

cords, it possesses a general relationship to all the portions 
of the living body, which look up to it for a maintenance. 
Placing the heart entirely beyond the reach of the in- 
constant, unstable will, was indeed a happy circumstance 
in the economy of our being. No one can put a stop to 
the pulsations of his heart, in a fit of despair or rage, as 
thousands would, were it possible. It still works on, by 
night as well as day, though the intellect sleeps, — and 
thus we are safely protected. If the pulsations and the 
maintenance of life, through the heart's agency, depend- 
ed on our vigilance, how soon we should forget the charge, 
and suffer the chronometer of life to run down the first 
time it was left in our care. Wisdom, — the manifesta- 
tions of an Ever Living, Omniscient Deity, are displayed 
at every stage of anatomical research. 

HEART-CASE, OR PERICARDIUM- 

An allusion, merely, has been made to the heart-case, 
ox pericardium, the office and importance of which is very 
likely to be overlooked. It is the membrane which far- 
mers sometimes make money purses of, on account of its 
softness, toughness and capacity. In the chest, lying be- 
tween the breast bone in front and the spinal column be- 
hind, it is like a bag, kept on the stretch by a hoop : on 
either side are the lungs, confined, however, in their own 
appropriate cavities. A duplication of its inner coat in- 
vests the substance of the heart, closely, and on the sur- 
face, spread over the heart, as well as from the inside of 
the pericardium, a halitus is exhaled, that lubricates the 
cavity, — admitting the gentlest possible motions, as it 
swings in the apartment. Though the heart is moving 
about, its apex being sometimes at one point, and some- 
times at another, according to our position, the pericar- 
dium never moves from its place, being always kept upon 
the stretch. 



ANATOMICAL CLASS BOOK. 

Fis. 56. 



133 








Explanation of Fig. 56. 
a, the heni't, in its natural position, the sternum beincr taken away, 
and the pericardium laid ojlen, in front, to give a full and perfect view 
of the organ ; c. is the arch of the aorta, or primitive artery of the 
body, from which all others arise; e, is the diaphragmatic nerve, 
having its origin high up, on the side of the neck, and travelling 
down into the chest, on the outside of the pericardium, or heart 
case, to reach the diaphragm, — the partition that divides the chest 
from the abdomen. If this nerve is divided, all motion in the dia- 
phragm will cease. It should be recollected that it is a muscle of 
respiration, — rising and falling with the inflation and collapse of the 
lungs. The base, or rather underside of the heart, as it is suspend- 



12 



134 



ANATOMICAL CLASS BOOK. 



ed from above, rests on the diaphragm at the lower b ; &, b, i, the 
heart case ; d, the descending cava, or great vein that returns the 
blood from the head and arms, into the right auricle of the heart. 



ARTERIES. 

To describe the arteries in a manner intelligible to per- 
sons who have never examined an anatomical preparation, 
in which these vessels are distended with wax, is certainly 
a difficult undertaking. 

Fig. 57. 




ANATOMICAL CLASS BOOK. 135 

Explanation of Fig. 57. 
By referring back to the plan of the perfect double heart, i shows 
the origin of the carotid artery, a branch from the arch of the aorta. 
In this very accurate plan of the superficial arteries of the head, a 
is the continued trunk of the carotid artery : it is this vessel which 
is usually divided by suicides ; it is this vessel also, with its mate 
on the other side of the neck, which, when compressed, causes ap- 
poplexy and death. /, the occipital artery ^ going to the muscles on 
the back of the head ; &, is the larynx, or vocal box; c, indicates 
the place where the carotid divides into the n, the external carotid^ 
branching onward; 6, also is the superior thyroid artery; ;?, the 
thyroid gland, and inferior thyroid artery ; /r, the temporal artery, 
felt beating in the temple, and sometimes selected to bleed from in 
desperate cases ; o, the left subclavian artery ; Z, the masseter mus- 
cle ; h, depressor anguli oris, having running under it the external 
maxillary artery ; i, the zygomaticus major, directing the eye also 
to the coronary arteries of the lips ; q, the nasai artery ; r, the ter- 
mination of the temporal artery, in minute twigs on the top of the 
head. 

After all that is said about the catalogue of arteries laid 
down in the human body, there is really hut one artery^ all 
others being branches from it. But to answer the purpos- 
es of the surgeon, it is absolutely necessary to treat of 
each twig distinctly, in order that its relation to other parts 
may be impressed on the mind of an operator. 

This one artery, the primitive trunk, is the aorta^ rear- 
ing itself out of the left ventricle of the heart : collectively 
the parent tube, with its subdivisions into thousands of 
tortuous pipes, is denominated the aortic system; and 
when arteries and veins are spoken of together, as a whole, 
the term sanguiferous system is used. 



136 



ANATOMICAL CLASS BOOK. 

Fig. 58. 




Explanation of Fig, 58. 

This diagram may be regarded as perfectly true to nature. The 
design is to show how the blood is conveyed to deep seated muscles 
of the face, and to the membranes covering the brain, within the 
skull : — all the vessels now under the eye, are branches, originat- 
ing from the trunk of the external carotid artery, shown in the pre- 
ceding plan. «, is the middle ov crredt meningeal artery of the dura 
mater. By the side of the ear, lies the trunk of the internal maa;- 
t7/arv artery, supplying a vast quantity of blood to the muscles of 
the face ; part of the jaw and the process of the temporal bone is re- 
moved, to explain the manner of its course under and about them. 
6, a branch of the inferior maxillary artery, seen in the other plan : 
c, 'posterior temporal branch ; d, pterygoid arteries, supplying those 
muscles which move the jaw, in chewinjj ; i, buccal artery, going 
to the buccinator, or trumpeter's muscle ; f anterior deep temporal 
branch ; e, infra orbitar artery. 

The bone in this figure, is supposed to have been taken away, in 
order to exhibit the arteries a which branch, like the limbs of a 
tree, over the surface of the dura mater. 



ANATOMICAL CLASS BOOK. 



137 



As the great cylinder rises above the top of the heart, 
thick, while and shining, it is bulged out at the sides, in 
in three directions, at the place where the three semilunar 
valves are fixed. The enlargement is known as the sinus 
of Valsalvi, from its supposed discoverer. Gradually it be- 
comes smaller, preserving, however, a diameter equal to 
three fourths of an inch, till it gets above the heart, where 

Fig. 59. 




Explanation of Fig, 59, 
This figure has been introduced to show the manner of supplying 
the brain with arterial blood by the vertebral arteries. It will doubt- 
less be recollected by the critical student, that in the side arms of 
the vertebrae of the neck, there were round holes, from one bone to 
the other. Through those holes, an artery creeps securely into the 
skull, unexposed to the thousand accidents to which the carotid ar- 
teries are liable. If, for example, an operation requires that the 
carotids should be tied, so that no blood can pass in them, a supply 
for the brain is secured by these vertebrals. When they have ar- 
rived within the skull, at the underside of the brain, the two mark- 
ed &, &, unite into one — which is c, — and then branches off among 
12* 



133 



ANATOMICAL CLASS BOOK. 



(.he convolutions of the brain, indicated by the various letters; g, 
is the Uttle brain or cerehellum ; /, the middle lobe of the brain, or 
cerebrum; e, the anterior lobe of the rerebriim ; and a, the optic 
nerves, or nerves of vision. This is no fanciful distribution of the 
arteries of this organ, but a perfectly true representation. 

it is gracefully curved over and upon the spine, down 
which it runs the entire circuit of the chest and ahdomen. 
On the hist joint, though not constantly, of the back, it 
divides into two trunks, to be sent to the inferior extremi- 
ties. On the highest point of the arch, branches shoot off, 
to carry blood to the head and arms. Those going up the 
side of the neck, are the carotids^ the arteries which 
suicides divide in cutting their throats. It is by com- 
pressing these, as in hanging, that death is produced : — 
when they arrive at the angle of the under jaw, they divide 
into external and internal carotids : — the deep seated or 
inner ones go through an orifice in the bottom of the skull, 
to supply the brain ; while the extermals creep up by the 
side of the ear, face, &.C., supplying all the muscles and 
bones in the vicinity. 

Fi-. 60. 




ANATOMICAL CLASS BOOK. J 39 

Explanation of Fig, 60. 
A veiy large quantity of blood, as we have seen, is sent to the 
brain, bj^ four arteries, viz. the two carotids and two vertebrals. By 
this plan, it will be plainly understood how the blood gets' bacli 
again to the heart. The superior longitudinal sinus, Fig. 1, is 
nothing more than a vein, — of a triangular shape, beginning'with- 
in the skull, opposite the root of the nose, and going backward be- 
tween the bone and outer membrane of the brain, over the' top 
of the head — increasing in size as it goes, till it reaches the level of 
the posterior lobe, — where it divides into two canals, marked 3. 3. 
Many twigs of veins, pointed out by the other figures, bring the 
blood from other places in the head, but ultimately, they all join one 
or the other br inches of the main trunks of the sinus : 3. 3. are 
called lateral sinuses, because they are on the sides, as it were of 
the head. Thesa two trunks pass^through a fissure, in the under 
side of the skull, between the temporals and occipital bone, and ap- 
pearing by the side of the neck, are there called the jugular veins. 
The external jugulars return the blood from the face, &c, and finally 
join the internal jugulars, — and there, by entering the chest, be- 
come enlarged by the union of the veins of the arms — wheri the 
whole are concentrated in one tube, — that last one, is the descend- 
ing vena cara, — emptying all the blood from the head, and bi-ain 
and arms, into the auricle of the right heart. The jugular veins' 
therefore, are the great veins of the brain, and commence behind the 
forehead bone, just between the eyes, within the skull. 

At the last joint of the spine, the lumbar region, we left 
the descending artery, divided into two branches. In as- 
cending from the heart, the large artery is called the as- 
cendifig aorta, and having made the curve, the descend- 
ing tube is the descending aorta. 

These two trunks, now lying just within the brim of the 
pelvis, divide again, sending a supply of blood to the 
muscles and apparatus within the pelvis. The first trunks 
are the external iliacs^ and the second set are internal 
iliacs. Further down, in the thigh, in each limb, the 

arteries appear under the name of femoral arteries : in 

the ham, behind the knee joint, the poplitceal; still fur- 
ther, by the side of the shin bone, the tibial ; in the foot 
the planter, and so on, till the divisions become too minute 
to be discernible to the naked eye. 

Between the arch and the pelvis, various little twigs 
are thrown off laterally to nourish the lungs, diaphragm, 



140 ANATOMICAL CLASS BOOK. , 

liver, stomach, spleen, and other abdominal viscera, — 
each bearing a name indicating its destination, or office, 
or supposed resemblance to familiar objects. Here, then, 
we have exhibited a scheme of the arterial system, per- 
haps quite as well as to have accompanied the text with 
many more drawings. 

The arteries must be nourished themselves, by a free 
circulation of blood in their coats, as much as the heart ; 
otherwise, were they independent of the rest of the living 
body, they would be extraneous, and could not contribute 
to its wants. On the sides of all the arteries, millions of 
vessels, infinitely fine, more nearly like the down on a 
peach than arteries, conduct a circulation. This tissue or 
net work of miniature arteries, is the vasa vasorum. 
Finally, the arteries are made up of several coats, as though 
one tube were thrust into another, -—which are muscu- 
lar and membraneous, according to their importance. 

As they recede from the heart, the tendency is to keep 
subdividing, to supply every possible part, — hence, ulti- 
mately, they become too small to be seen. Between these 
points, and the commencement of the veins, is an inter- 
mediate set of real or imaginary vessels, the capillaries, 
through which the blood must pass to reach the veins. 
Such is the monstrous size of the aorta in a whale, that 
the whizzing velocity of the blood, at each systole, is 
audible to the harpooners : with the stethoscope, quite a 
modern invention, the rush of the blood may be heard in 
our own species. 



ANATOMICAL CLASS BOOK. 



141 



Fig. 6L 




Explanation of Fig. 61. 

It is utterly impossible as 
well as unprofitable, in an el- 
ementary work of this kind, 
intended for youth, to picture 
every vessel ; but we were 
desirous of (Usplaying the ar- 
teries of the arm and palm of 
the hand, on account of the 
beauty and great importance 
of the structure. What is 
seen in this drawing, exists in 
every living arm. Over the 
bend of the elbow, a mere 
web lies between the great 
artery and vein. The vein is 
taken away, but it will show 
how dangerous it is to bleed 
the vein, at this point, on ac- 
count of the neainess of the 
artery, which is liable to be 
wounded by the point of the 
lancet. A knowledge of this 
fact, should deter every one 
from employing surgeons in 
whom they have noi the most 
implicit confidence, that they 
understand anatomy, a, b. c, 
d, e, /, g. h, k, mark the 
hT^nches oi the brachial art 67^ 
a, as they are, in relation to 
the muscles ; i is the fassia or 
the men)brane, between the 
artery and vein, and which is 
a tendinous strip sent off from 
the biceps flexor cubiti or 
bending muscle of the fore 
arm, as though it was express- 
ly designed to confine the 
throbbing aitery in its place, 
and protect it from the injuries 
to which it seems liable by 
carrying burdens in the arms. 
This strip of tendon is like the 
arch of a bridge, — for if the 
arm is bent, it is still tense, 
and therefore always a de- 
fence. 

This brachial artery, near 
the elbow, divides into branch- 



142 ANATOMICAL CLASS BOOK.*: 

es; — one of them sinks into the muscles, to supply them, by the 
side of the ulna, on a line with the little finger, and hence called the 
ulnar artery. The main trunk of the brachial^ however, travels 
downward, quite superficially, near the edge of the radius, and 
therefore has the name of radial artery. In the wrist, being just 
under the skin, it is pressed against the bone, where its pulsations 
are felt : — feeling the pulsp, in the language of physicians, simply 
means the sensation conveyed by the throbbings of this artery, when 
thus compressed. Further on in the pahu of the hand, it forms half 
a circle, termed the pahner arch, and from its outward curve, digital 
branches convey the blood to the fingers and thumb. 

That the arteries possess the property of contracting 
upon the blood cannot be denied. The heart, were it in- 
tended to force the column, independently of any assis- 
tance from the arteries, through their whole extent, we 
should suppose, was not adequate to the undertaking, be- 
cause the proportions are unequal, in comparing the engine 
with the distance to which it is required to send the blood. 
The pulsations of the arteries, indicate that they continue 
and propagate the action which was commenced by the 
heart. 

Were it not so, of what use are the valves at the mouth 
of the aorta and in the pulmonary artery ? If the volume 
to which an onward impetus had been given, could pur- 
sue the tortuous windings, quite to the capillaries, of what 
need were the valves ? The truth appears to be this, viz., 
the ventricle only throws the blood beyond the valves, 
which are thrust across the canal to prevent a regurgita- 
tion, and then the artery compresses it in turn. Onward 
it moves, to some other place, where, before the velocity 
that has been given it is lost, a second, third and fourth 
pulsation, as the case may be, conpletes the circle of ac- 
tion, Do we not actually feel that the artery pulsates in 
the wrist ; and do we not also recollect that in the fish, an 
artery, the aorta, assumes the office of a heart ; in the 
vermin too, did we not show that the aorta and accompa- 
nying arteries carried on the perfect circulation, without 
any heart at all ? 



ANATOMICAL CLASS BOOK. 143 

The arteries are not passive tubes, imbedded in the 
concealed interstices of the muscles to conduct a fluid in 
which they have no part nor interest. They are not qui- 
escent, like the wooden pump logs of an aqueduct corpo- 
ration, remaining at rest, till something disturbs them : — 
no ; they are portions of a living whole, endowed with a 
vitality which results from this peculiar combination of or- 
ganized matter. They feel the vigor, or the decay of other 
parts ; they become diseased by over excitement ; sicken, 
refuse to pursue their accustomed service ; and when the 
crazy, shattered frame of the old man begins to tottle, the 
arteries, too, begin to flag, and finally cease to act at all. 
In old age they ossify — becoming perfectly bony tubes, 
for many inches together : by over action, they are en- 
larged into irregular sacks, or aneurisms ; and in ad- 
vanced cases, they bursty and the heart's blood is wasted 
so quickly, that life may be said to have exploded. 

The tendency 'of age, is to relax the muscular fibre, and 
in this general debility, the arterial coats suffer — their 
diameters enlarge, and their power is diminished as their 
transverse diameter increases. The energy of the pulse 
is lost; the arteries, however, make an effort to sustain 
their accustomed vigor, by assuming a more tortuous 
course, — showing, that the short curves which are made 
under these circumstances, are favorable to the accumula- 
tion of physical power. 

VEINS. 

It is much easier to account for the propulsion of the 
blood from the heart, through the arteries, than to explain 
the process of its return through the veins. Their origin 
is in the capillaries, quite at the extreme terminations of 
the arteries, growing larger as they advance towards the 
centre of the body. They are seen through the skin at 
the ends of the fingers, on the arms, and indeed every- 



144 



ANATOMICAL CLASS BOOK. 



Fig. 




Explanation of Fig. 62. 

The anatomy of the veins being 
much less intricate than the arteries, 
to understand, it has not been thought 
necessary to present more than one 
plan of some of the most superficial 
y vessels of this order. 

On the calf of the leg, there are 
numerous veins, just under the skin, 
uniting into fewer and fewer branches, 
as they rise upon the limb, till they 
finally unite in two principal trunks, 
one deep seated, and the other super- 
ficial, which pass into the pelvis, at 
the groin, and thus convey the blood to 
the ascending vena cava^ the great 
vein that carries all the blood to the 
heart, which has been collected below 
it. By turning to the drawing of the 
double heart. Fig. 2, that great vein 
will be seen. 

d. The gastrocnemius. 

€. The nervas saphaenus minor. 

/. The branch arising from the pop- 
liteal. 

g. The nervus communicans, aris- 
ing from the fibular nerve. 

h. The popliteal nerve. 

I. The fibular nerve. 

k. The popliteal vein. 

Z. The vena saphaena minor. 

m. The popliteal artery. 

n. n. The arteriae, distributed upon 
the calf of the leg. 

p, p. The muscles on the back of the 
thioh. 

d. The gastrocnemius. 



where, creeping upward, becoming increased in size at 
every step, till they eventually are reduced in number to 
two principal trunks, the superior and inferior cavas, at 
the right auricle. Their coats, which are the same as the 
arteries, are thinner and weaker — more dilatable, and 
consequently much oftener diseased and liable to acci- 



ANATOMICAL CLASS BOOK. 145 

dents. Through their whole track, with a few excep- 
tions, there is a line of valves, the office of which is to 
hold the column from falling back, that has once passed 
above the lock. So frequent are these valves, that they 
may be detected every inch, in the great veins of the arms. 
By compressing the vessel above one of them, the blood 
at once accumulates in the form of a knot, — showing ac- 
curately the exact place of its locality. The principle of 
fixing a ligature round a limb, as a preparatory step to 
bleeding, with a lancet, is to stop the blood in its course, — 
there being no possibility of its going backward, as it is 
held by the valve, — therefore, as the canal is closed by 
compression above, the escape is at the incision. 

We will not pretend to inform our readers how the blood 
travels up the veins, — lying, as they do, perfectly quies- 
cent. It seems as though there must be a propulsive force 
exerted somewhere in the vicinity of the capillaries, to 
thrust the blood along, yet dissection gives us no clue to 
the mystery. 

The veins also perform other interesting duties, acting 
as absorbents, accompanying the arteries, wherever they 
may go, to be servants in waiting, — to pick up, and carry 
home whatever may have been conveyed to a distance by 
their superiors. 

CIRCULATION OF THE BLOOD. 

Were it not necessary in the plan of animal life to pre- 
sent every particle of blood, at certain intervals, to the 
influence of atmospheric air, there would have been no 
need of a heart. We might have been born with a suffi- 
cient quantity in our bodies, where it might have remained 
undisturbed, fulfilling the intentions of its design. Such 
a state of things, however, is not admissible, because it is 
secreted into the vessels to increase the growth, to repair 
13 



146 ANATOMICAL CLASS BOOK, 

the wastes, and to sustain the whole by its vivifying pres- 
ence. Every bone, muscle, tendon, nerve, membrane and 
fluid, is made out of the blood. As the parts to be made 
cannot fabricate themselves, and afterwards take their ap- 
pointed stations, the blood goes to the spot where this is to 
be effected, leaving material for a bone in one place, glue 
to hold particles together in another, and so on, in its ac- 
tive round. But, on the other hand, these particles can- 
not fashion themselves : — the point of an artery, there- 
fore, at which they are given off, assumes the office of an 
artisan, and moulds and finishes the work. 

We here discover that the arteries possess a wonderful 
property, which was not spoken of in the preceding para- 
graphs. Industrious and unerring in all the first years 
of life, invariably conveying just the sort of material that 
may be wanted to mend a broken bone, to heal a cut finger, 
or to lubricate a joint, they grow careless in forty years : — 
they neglect supplying the eyes with sufficient quantities 
of humors to distend the ball, so we meet the emergency 
by wearing spectacles: they are forgetful of the order by 
which their early labors were regulated, — and as one 
mistake leads to the commission of another ; lime is car- 
ried to the heart, where the valves become bony ; the 
urinary apparatus is carelessly watched, and stones form 
in the bladder ; the teeth are not supplied with earthy 
matter in season to prevent their decay : — the hair is not 
watered at the roots, and it becomes dry and falls oflf. 

Such cursory remarks as these, exhibit a bird's-eye view 
of the importance and multifarious functions of the arte- 
ries, and demonstrates the high value of the blood, from 
which so much and such inimitable machinery is formed. 

As we now comprehend the use of the circulation, we 
will next endeavor to solve another apparently difficult 
problem — the ivht/ it is necessary to throw the blood into 
the air cells of the lungs. 



ANATOMICAL CLASS BOOK, 

Fi?. 63. 



147 




Explanation of Fig. 63. 

If the student is desirous of thoroughly and clearly understanding 
cthe circulation of the blood, as it moves in his own body, let him 
now recapitulate the subject, by following the venous or black blood 
from the two gi*eat supplying veins, till it arrives in the main dis- 
1:ributii)g artery, purifiedj re-vitalized and in. a condition to sustain 
animal life. 

9, the descending vena cava, returning black blood from the head 
and upper extremities. 

o, the ascending vena cawa, returning tlie same kind of blood from 
the lower parts of the body. 

71, the right auricle of the heart, where both Telns meet. 

J), and X. veins from the liver^ spleen and bowels^ uniting with the 
inferior cava. 

The auricle being filled, contracts and forces the blood into h, the 
ventricle: next the ventricle contracts and sends it into /c, the'/ii(/- 
monary artery, which branches into Z, Z, to supply the lungs in both 
sides of the chest. Fi'om''the lungs, where a scarlet color has been 
^iven it, four veins of the lungs gather it together, and deposit it in 
the left auricle r; that contracts, and the blood is driven into the 
left ventricle a ; lastly, the ventricle contracts and throws it into c, 



149 ANATOMICAL CLASS BOOK. 

the aorta, which conducts it over and through every bone, muscle 
and organ. 

Under a solar microscope, the circulation of the blood in the thin 
w^eb of a frog's foot, and several other reptiles, may be distinctly ob- 
served ; and in insects, while they remain worms, the pulsations of 
the artery which acts instead of a heart, are readily perceived. In 
the oyster, the heart pulsates about thirty-seven times in a minute. 

Before birth, the blood, instead of going from the auricle of the 
right heart down into the ventricle, to be thrown into the lungs, 
passes directly through a valve in the partition wall between the two 
auricles, and thus gets into ihe left side or left heart. The reason 
why the blood is not sent to the lungs, is because they have not yet 
assumed the function of breathing. At biith, when the first breath 
of air is inhaled that ever entered the lungs, the valve closes up the 
opening forever, and the blood then takes a ciicuitous route through 
the lungs, for the reason which has been already so familiarly ex- 
plained. 

The sign of the vitality of the blood is its scarlet color? 
which it only exhibits in the heart and arteries. When it 
goes from the heart, it is charged with the presence, or 
admixture, of every material which can possibly be re- 
quired; but on its way to the capillaries, all these several 
materials, supposed to be in solution, are dropped on the 
way, so that when the refuse, that is, the fluid, which was 
merely the medium of conveyance, enters the extreme be- 
ginnings of the veins, its cplor is almost black. 

Having, therefore, imparted all its needful qualities, it is 
totally unfit to be sent round a second time, till it is re- 
charged. To obtain this quality, now lost, the rigid heart 
sends it into the lungs. Surrounding each distended air 
cell, is a thin sheet of black venous blood, which by the 
mysterious influence of the contained air, changes the 
color, instanter, to its original scarlet. The orgasm, the 
suddenness of the change, cannot be conceived — yet 
the whole mass is re-vitalized, and is now carried into the 
left heart, to be again sent over the old ground. Such, in 
familiar language, is the circulation of the blood — a pro- 
cess well calculated to raise our admiration for the charac- 
ter and transcendent power, and condescending goodness 
of our Creator. 



ANATOxMI€AL CLASS BOOK. 149 

Anatomists in treating of this important fluid, speak of 
its being composed of three substances, viz ; serum, the 
watery, yeliovvish fluid ;Jibrin, the crassamentum^ or cake ; 
and the coloring matter. Were we not restricted in this 
work to certain limits, it would certainly be an entertain- 
ing theme to detail the extravagant whims which the old 
authors entertained upon the subject of the red globules of 
the blood. It actually seems, to a calm spectator, who 
surveys the past and compares it with the present, as 
though the physiologists of the two last centuries bowed 
down to make themselves positively ridiculous, by the 
sweat of the brow. When, by some fortuitous circum- 
stance, it was ascertained that the florid hue of the blood 
depended on the actual pressure of floating globules, of 
different sizes, yet so minutely small as to appear like the 
coloring of an infusion, they set to work in earnest to in- 
vestigate their use and structure. About the same time, un- 
luckily, a philosopher invented the compound microscope, 
which enabled every body to peep into microcosms, where 
they beheld sights, quite imaginary in most cases, more 
astonishing than were ever before revealed to human eyes. 

Whether they saw distinctly or not, it is now of little 
consequence ; but at all events, they asserted the want of 
uniformity in the size of the globules, though each one 
was a hexagon, built up regularly and mathematically, as 
an architect could construct a country seat, of six smaller 
hexagons ! However small — and some where supposed 
to be immensely beyond the magnifying reach of their 
glasses — they were all framed in the same workman-like 
manner. 

All this fine discovery being settled and indisputably 
admitted — for it would have been outrageously impolite 
for those who had no microscopes, to call the marvellous 
discovery in question — their wits were in labor to devise 
a rank for them in the circulation. This, too, was accom- 
13* 



150 ANATOMICAL CLASS BOOK. 

plished; but to find out the diseases that originated in 
consequence of the mistakes, or refractory conduct of the 
compound balloons, was a poser. There is nothing, by 
the way, like perseverance. A man who is lost in a fog, 
has but one course to pursue, and that is to take care of 
himself: so it was with our discoverers; they had their 
mathematical bladders on hand, which must be disposed 
of — and here they are, in all their beauty of arrange- 
ment, from the plastic hands of their discoverers. 

Diseases were the effects arising from error loci — that 
is, some of the large globules, fitted to the calibre of a par- 
ticular artery, got wedged by some sad mishap at the 
mouth of a smaller vessel, or, becoming angry, refused to 
operate in the harness, so puff'ed up — clogged the pass- 
age — and this produced infiammation, out of the modifi- 
cations of which fevers, dropsies, and all the other ills that 
flesh is heir to, had a bona fida origin ! 

Enough has been written to stimulate our readers to 
the perusal of the old records of physiological folly, in the 
original tongue, if they wish for an uninterrupted history 
of that singular discovery. To those who are more inter- 
ested in the anatomical facts we have been relating, 
touching the heart and the arteries, it is needless to re- 
commend them to the writings of those who are^ teachers 
by profession. Perhaps we may have committed ourselves 
in the ardor of the moment, by advancing ideas quite as 
absurd as those which we have been condemning ; but in 
the demonstration of parts, we are conscious of being right, 
having given the anatomy of the circulation as we have 
found it, by years of toil ; and as it regards theories, things 
made at little expense, like castles in the air, we are not 
tenacious about the respect that may be paid to them. 
Having been right merry over the conceits of our profes- 
sional predecessors, we are quite willing to be laughed at 
in turn. 



ANATOMICAL CLASS BOOK. 151 



QUESTIONS. 



Had the ancients a knowledge of the circulation ? 
How did they explain the movements of the blood ? 
What is the heart ? 

Is the heart a single or compound organ ? 
In what animals is the heart single ? 
Why is it necessarily single in fishes ? 
How does it act? 

How many cavities has the heart ? 

What prevents the blood from rushing into the wrong apart- 
ments ? 
Has it a circulation of blood for its own service ? 
What are the auricles ? 
What are the ventricles ? 
What is the use of the valves ? 
Has the heart any nerves ? 
Why has the will no control over it ? 
Where is the heart located ? 
Is it covered by any membrane ? 
Why are not the pulsations felt in the right side ? 
How does the right heart differ from the left ? 
What is an artery ? 

Where is the principal artery of the body found ? 
What veins return all the blood to the heart ? 
Are there valves in the veins ? 
Has the aorta any valves ? 



152 ANATOMICAL CLASS BOOK. 

Where does the pulmonary artery arise ? 

Where are the carotid arteries ? 

By what arteries is the brain supplied with blood ? 

Is the heart a forcing engine ? 

How are the pulses perceived in the wrist? 

What is the use of the pericardium ? 

What change is effected on the blood in the lungs ? 

What color has the blood in the veins ? 

What color has the blood in the arteries ? 

Does blood circulate in the bones ? 

By what organs are all parts of the body fashioned ? 

Of what use is the blood in an animal ? 

How is the blood supplied ? 

What is the object of taking food into the stomach ? 

Is it known by what power blood is moved in the veins ? 

What is the composition of the blood ? 

Why are some animals denominated cold blooded ? 

Is the blood warm in reptiles having a single heart? 

Can any animal exist long, deprived of its heart? 

What is understood by the irritability of the heart? 



ANATOMICAL CLASS BOOK. 153 



THE NERVES, 



OR NEUROLOGY. 



Neurology teaches us the anatomy and physiology of 
the nerves. 

The brain is the radiating point whence the nerves, 
to a considerable extent, have their origin. The spinal 
marrow, from which an immense number of nerves branch 
out, is considered in reality by some, a prolongation of 
the brain itself. Phrenologists, on the other hand, sup- 
pose the brain arises from the spinal marrow, because the 
brain is sometimes wanting, but the nerves are always 
present. 

In the first place, the contents of the head are divided 
into the cerebrum and cerebellum^ or in other words, the 
great and small brains. Above the level of the ears, all 
the upper portion of the skull is occupied by the cerebrum, 
which is the immediate seat of intellect. Below that level, 
in the lower and back part of the head, is the cerebellum 



154 



ANATOMICAL CLASS BOOK. 
Fig. 64 




JExplanation of Fig. 64. 
This is an exhibition of a vertical section of the bones of the head, 
face and brain, showing precisely the appearance, were the head di- 
vided in the middle, from the top, down to the neck. No letters of 
reference have been introduced, because the plate will be doubly 
valuable, when the general relation of the different portions have 
been learned from the text and the other diagrams. The reader will 
then trace wath his eye the outline of the little brain, the cerebrum, 
or large brain, the seat of thought; the ventricles and other interest- 
ing points, which, though intricate, are nevertheless worth the trou- 
ble of understanding. The mechanical arrangement is only contem- 
plated in these illustrations: — the functions of the brain in a treatise, 
purely elementary, would be wholly useless. 

or little brain. They are separated from each other by a 
membrane, tensely stretched. Otherwise, the weight of 
the upper mass wotild oppress the functions of the lower 
one. By a vertical line, the brain is divided into heyni- 
spheres, as right and left : but when it is dislodged from the 
head, and inverted, the underside presents three promi- 
nent risings, which are denominated lobes. Those por- 
tions of the brain directly behind each eye, are the ante- 
rior lobes. Those at the back side of the head, the poste- 
rior; and the third, between them both, are the middle 
lobes. 



ANATOMICAL CL.ASS BOOK. 155 

COATS OF THE BRAIN AND NERVES. 

In this plain exposition of the anatomy of the nervous 
system, it would be an endless labor to attempt a minute 
detail of the three different coverings, which surround the 
intellectual apparatus, independently of the bony box, the 
strong wall that envelops the whole. 

FIRM COAT, OR — Dura Mater. 

When the skull is opened, a dense, shining membrane 
is presented, that keeps the brain together, when the 
bones are taken entirely away. Completely embracing 
the entire organ, it becomes thicker round the medulla 
ohlonga^ to defend this narrowing of the brain, over the 
bones of the neck, — then continues its course through 
the whole length of the back-bone, embracing the mar- 
row : wherever a branch or side nerve is given off, a por- 
tion of the dura mater follows it, precisely as the bark of 
the trunk covers the branching limbs. In the still smaller 
divisions of the nerve, a continuous tube of the dura mater 
is found, till both are finally lost on the exterior surface. 
This membrane, let it be remembered, holds the office of 
defending the pulp of the nervous matter within its em- 
brace, wherever the nerves may traverse, 

TRANSPARENT COAT, OR — Tumca Aracliuoides. 

Perhaps there is not a more delicate, transparent mem- 
brane in the whole body than this, — so much resembling 
a spider's web, that from this circumstance it has its name. 
This lies over the convolutions of the brain, directly under 
the dura mater, and does not dip down between the pro- 
minences. Beside surrounding the brain, like the other, 
it has precisely the same infinite distribution — making 
the second tube for defending the nerve. 



156 ; ANATOMICAL CLASS BOOK. 

SOFT COAT, OR — Pta Muter. 

Blood must be everywhere freely circulated; but in the 
brain, it is necessarily thrown into that portion which is 
the seat of thought, in very minute, hair-like currents, — 
otherwise the force of the heart, which acts upon the 
principle of a forcing-pump or syringe, would tear it to 
pieces. This pia mater, therefore, is an immense, broad, 
thin net of blood-vessels, following the fissures and wind- 
ing into the very centre of the brain, and also pursues the 
nerves, wherever they may go, always in attendance to 
furnish the vital fluid, on which health, sensibility, and, 
indeed, all the vital functions are forever depending. 

STRUCTURE OF THE BRAIN. 

The centre of the nervous system is the brain, within 
the bones of the head, with the exception of that class 
of animals, which, as it were, are the uniting links be- 
tween the vegetable and animal kingdom; — the worms 
are without it : fishes too, and amphibious reptiles have 
scarcely a development of the nervous mass, entitling it 
to the appellation of brain. We suppose, however, that 
we are contemplating the human brain, a singular, but 
splendidly constructed piece of mechanism, made up of 
an infinite congeries of delicate cords, — and equally at- 
tenuated blood vessels. 

It was once thought that we had but one brain, but 
modern discovery assures us that we possess four ! and that 
two of them mutually cooperate, in function, with the 
others. 

There is no particular point where the brain can be 
said to begin, nor a point, in fact, where it terminates. Let 
the reader suppose that on the first joint of the neck, just 
under the head, two large cords are lying, side by side : 
entering the great natural opening of the skull, they are 



ANATOMICAL CLASS BOOK. 157 

subdivided into millions of threads, — portions of which 
assume different forms, to which anatomists give specific 
names, — as cruri, pons, &:/C. But as the threads are 
merely subdivisions of the one cord, — the mystery is, at 
first view, how comes such an increased quantity ? noth- 
is more simple than an explanation. Admitting the fibres 
to be indefinitely long, — the folding and refolding of one 
upon another, in conjunction with an artery and vein — 
there is no difficulty in giving an answer. For the evi- 
dence of a fibrous structure, this infinite volume of threads, 
we refer to the positive demonstration of the brain by the 
late Dr Spurzheim. 

Most of the organs are double, and it was highly neces- 
sary that the brain should be so also. The great brain 
cerebrum, in the upper part of the head and over the eyes, 
is the immediate seat of intellect, and in halves; in 
other words, there is one on each side, divided, above 
from each other, in the middle, by a membrane. Under 
this, in the lower and back part of the head, is the cere- 
bellum, or litlle brain, belonging to the animal system, 
and totally different in function from the other; this too, 
is in two pieces. 

Below the point on the neck bone on which the two 
lateral cords, termed medulla ohlonga, lie, extending with- 
in the bones, the whole length of the spine or back-bone, 
the same cords are seen — giving out, between the points, 
ribs, &/C, branches, — called spinal iierves. Those within 
the chest take the name o^ thoracic nerves; — still lower, 
between the ribs, intercostal^ and still further down, be- 
tween the bones of the back, the lumbar nerves. The 
limbs of a tree, shooting out from the trunk, precisely rep- 
resent this part of the anatomy of the spinal marrow. 

Let it be remembered, that, from the head to the termi- 
nation of the spinal marrow, two cords, two brains, tico 
little brains, and two distinct sets of lateral nerves exist 
14 



158 ANATOMICAL CLASS BOOK 

lying, however, in juxtaposition, intimately united by the 
decussation of fibres, which run from one to the other. 

This cerebral substance is so soft, that without its en- 
veloping membranes, it would fall to pieces, by its own 
weight. These membranes possess but a very slight de- 
gree of sensibility ; — being of a mealy whiteness, and in 
the skull possessing but little elasticity, though in the body 
and limbs, this quality necessarily exists, or they would 
become elongated and flaccid in the constant flexions of 
the extremities. 

Whilst this nervous matter preserves its vitality, it pre- 
serves a slight degree of cohesion, but after death, it 
speedily begins to decay, and ultimately melts down into 
an oily fluid. As before remarked, the composition of the 
pulp of the nerves and the brain, are precisely the same, 
in appearance, in life, and chemical analysis conclusively 
presents the same elements after death. 

When wounded, even badly, the brain feels no pain, al- 
though the very centre of sensation. It is not uncommon 
for portions of the brain to escape through fractures of the 
skull, and yet the person perfectly recover, and never suf- 
fer, in any quality of his mind, from the loss of this impor- 
tant corporal substance. 

Let it here be recollected that all the nerves which go 
from the head or spinal marrow, however much they may 
be distributed within the muscles, invariably run towards 
the surface of the body ; they do not, however, end in blunt 
extremities under the skin, like the cut end of a twine; — 
on the contrary, they are so infinitely subdivided, that the 
single cord which we find between two points of the spine 
may finally become a perfect brush, in the course of dis- 
tribution, and lost in the masses of flesh through which 
it travels, till it can no longer be recognised by the 
naked eye. 



ANATOMICAL CLASS BOOK. 

Fig. 65. 



159 




Explanation of Fig. 65. 
Sy the annular ligament which binds down the muscles and vessels 
to the ankle bone, to keep them in place, i?, the extensor brevis 
digitorum, which assists in extending the toes. Fig. 1, superficial 
threads of the deep seated nerves of the leg and instep, emerging upon 
the top, and losing themselves in the skin. Fig. 2, are long, but 
superficial cutaneous branches of the tibial nerve, sent into the skin 
and cellular membrane at the root of the toes and ball of the great 
toe. The trunk, from which these twigs have their origin, originated 
within the pelvis, yet, notwithstanding they were concealed, deep 
in the flesh, the whole length of the limb, they finally make their 
appearance at the surface. This figure, therefore, is designed to il- 
lustrate the position maintained in the text, viz, that all the nerves 
have a direction towards the external surface of the body. 



THE MECHANISM OF THE NERVES. 

As the brain, all experience proves, is the seat of intel- 
lect, so also, incontestible evidence teaches us that the 
nerves are parts which are susceptible of painful or pleas- 



160 ANATOMICAL CLASS BOOK. 

urable sensations. Thus a piece of sugar is grateful to 
the gustitory or tasting nerves of the tongue; — but to- 
bacco, before accustomed to its nauseating character, has 
a directly opposite effect. Pressure on the sciatic or great 
nerve of the leg, by sitting too long in one position, pro- 
duces the disagreeable feeling, commonly called sleep in 
the foot; if, however, the attitude is not changed, to re- 
lieve the pressure, a partial palsy of the limb must ensue. 

Difficult as it is to ascertain precisely, the structure of 
the inner substance of the nerves, it is reasonable to infer, 
from analogy, as the substance is so exactly like that of 
the brain, that they are constituted of a multitude of mi- 
nute, soft, pulpy parallel cords. Instead of saying that the 
nerves have their origin in the brain or spinal marrow, 
they should be called the prolongations of the brain. Their 
internal substance, both physically and chemically con- 
sidered, presents the same results. They are the tenta- 
culse of the brain,- — analogous to the feelers of insects, 
by which it takes cognizance of external things: — the 
instruments of the will, and the ever faithful sentinels at 
the outposts, giving the earliest and most certain intel- 
ligence of whatever is of consequence to the safety and 
well being of the individual. 

If they possess an organization like the brain, or in fact, 
are simply a prolongation of it, into the extremities of the 
limbs, the question may be asked why they are not con- 
scious, in their individual capacity — and why it is neces- 
sary to make reference to the superior mass of the same 
material, within the skull ? 

In the very lowest orders of animals, such is the case, to 
a certain extent : the worms are without brain, yet they 
pursue unvarying instinctive actions, and avoid enemies 
or caress friends, with as much certainty as those pos- 
sessing a well marked one. 

Nothing can be more perplexing, than the nerves, being 



ANATOMICAL CLASS BOOK. 



161 



of all sizes, from a quarter of an inch in diameter, to hair 
like threads, invisible to the naked eye. 

Certain it is, that this apparent confusion presents the 
same appearance in all animals of the same species : 

Fig. 66. 




14* 



162 ANATOMICAL CLASS BOOK. 

^Explanations of Fig. 66. 

MUSCLES. 

A. Pectoral muscle. 

B. Detoid muscle. 

C. Latissimus dorsi rauscle. 

D. Serratus major anticus muscle. 

E. Biceps Flexor Brachii. 

F. Round tendon of the biceps^ crossing the elbow joint. 

G. The broad expansion of the biceps, shooting into the fassia of 
the fore arm. 

H. Triceps extensor muscle. 

I. Br acheus inter nus muscle, ?Ln 2i\\x\\\divy io Xhehiceps. 
K. Coraco Brachialis muscle, an assistant to the deltoides. 
L. Supinator Brevis muscle, turns the pahn of the hand and fore 
arm foi ward. 

M. Supinator longus, operates in unison with the brevis. 
N. Extensor Radialis Longior, extends the fore arm. 

0. Many flexor muscles of the fingers, all arising from one point. 
P. Flexor digitorwn profundis, bends the joint of the fingers. 

R. Annular ligament of the wrist, bending the tendons in a 
groove. 

S. Short muscles, forming the ball of the thumb. 
T. Flexor and abductor muscles of the little finger. 

NERVES. 

1. 1. Radial nerve. 

2. 2. Ulnar do. 

3. External cutaneous nerve. 

4. Muscuhr spiral nerve ; supplies the flesh on the back side of 
the arm and skin. 

5. A communicating twig. 

6. Articular nei-ve, round the joint. 

7. Internal cutaneous, supplies the skin under side of the arm. 

8. External cutaneous, again; passing through a muscle, and 
then becoming a cutaneous nerve. 

9. Branch of the external, going to the back of the thumb. 

10. Muscular spiral nerve. 

11. A branch of the external cutaneous. 

12. The radial nerve. 



TO rri 1 / different views. 

13. The ulnar nerve. 5 

14. A branch of the ulnar, to the back of the hand. 

15. Distribution of the radial nerve to the thumb, fore finger, 
middle and one side of the ring; finger. 

16. Distribution of the ulnar nerve to the other side of the ring, 
and both sides of the little finger. 

N. B. We have exhibited in this plate a mass of muscles and nerves, 
that the reader may have some idea of the complex machinery ne- 
cessary to the perfection of only one single limb. 



ANATOMICAL CLASS BOOK. 163 

wherever there is a twig in one body, leading to an organ, 
precisely such another, fulfilling exactly the same office, 
may be demonstrated in another : a curious illustration of 
this remark is strikingly manifested in the nerves of the 
human hand. 

The arteries are not invariably constant, or undeviating 
travellers of a particular muscle. With the nerves, the 
case is altered : — they are constant, as it respects the 
origin, course and ultimate distribution — go Vvhere they 
may, a precise number of branches are required, to be dis- 
tributed to every portion and piece in which a blood ves- 
sel enters. Usually, the deep seated nerves accompany 
the arteries ; and the nerves of the skin keep in the track 
of the superficial veins. 

Though the nerves are small, and uninfluenced by voli- 
tion, exact order is preserved, or the same effects could 
not be produced in two individuals, from the same causes. 

Without nerves, there could be no sensation : — with- 
out them, neither painful or pleasurable emotions would 
be recognised; without them, organized beings would 
be completely motionless, without locomotion, and with- 
out perception or consciousness. 

It matters not how perfectly the muscles are developed, 
or advantageously arranged, if there were no mode of sub- 
jecting them to the influence of the brain, —they would 
be of no kind of consequence. 

Were the nerves in the wrist divided, the ability to 
clench '.he fingers w^ould be lost ; nor can it be recovered, 
unless a re-union of the divided portions can be effected. 
These are the voluntary nerves. 

Those denominated involuntary^ administering to the 
involuiitary muscles, are equally important to the hidden 
regions in which they are found. When the breathing 
nerve of the diaphragm is separated, the midrif no longer 
renders assistance in respiration. The muscles of the 



164 ANATOMICAL CLASS BOOK. 

chest are compelled to carry on the process of breathing 
entirely alone. By dividing minute twigs, as they creep 
into the vocal box of a dog, the muscles are paralyzed, 
and the animal can never afterwards bark. 

Digestion in the stomach may be interrupted by cutting 
the main trunks of the nerves. Even the functions of the 
liver and kidneys might be checked in the same way, 
were it possible to reach the nerves going to them, with- 
out violence. 

Notwithstanding the heart is kept in continual nuiotio 
by the presence of the blood, if its nerves were separa- 
ted, so that the communication were interrupted with the 
brain and spinal marrow, it would cease to pulsate, though 
its irritability, an original endowment of the muscle, 
might remain a considerable time. And still further, a 
wound or compression of the spinal marrow completely 
paralyzes the whole body, — which, if not speedily re- 
lieved, ends in death. 

For the sake of method, anatomists have made a regu- 
lar classification of the nerves: — 

From the brain, there are nine pair — a majority of 
which are the nerves of sense ; — in other words, they 
are expended on the organs of sense, as the ear, eye, nose, 
and tongue. 

Issuing from between the bones of the neck, there are 
eight pair, — from between the joints of the spine, 
twelve ; — from the loins, five pair more ; — and the 
sacrum or last bone of the vertebral column, five more, — 
making a total of thirty-nine sets of nerves, from the 
brain and spinal cord. 



ANATOMICAL CLASS BOOK. 

Fig. 67. 



165 




166 ANATOMICAL CLASS BOOK. 

Explanations of Fig. 67. 
A A. Cerebrum, or brain. 
B B. Cerebellum, or little brain. 

C C. Crura Cerebri, or union of the fibres of the brain. 
D D. Crura Cerebelli, union of the two sides of the little brain. 
E E E. Spinal marrow. 

1 1. Branches of the 5th of nerves, so often noticed in this work. 

2 2. Branches of the sub-occipital nerves. 

3 3. Branches of the four inferior cervical nerves, and the first 
dorsal, formina; the axillary plexus, from whence all the nerves of 
the arm and fingers have iheir origin. 

4 4 4. 4. Branches of the dorsal nerves. 

5 5, Lumbar nerves. 

6 6, Sacral nerves. 

THIRTY PAIR OF SPINAL NERVES. 

These are first divided into Eight pair of Cervical, 
coming out between the bones of the neck, on either side, 
from the spinal marrow, — to be distributed to the muscles. 

Tioelve pair of Dorsal, — in like manner, coming out 
between the dorsal vertebrae of the back. 

Five pair of Lumbar , — from between the lumbar or 
joints of the loins. 

Five pair of Sacral^ — being a branch or termination 
of the spinal marrow in the os sacrum. Several cords, 
coming through the several openings, unite to form the 
great sciatic nerve of the leg. 

Another circumstance should not be lost sight of in 
this general survey of these organs — viz., the well estab- 
lished fact, that two threads may arise from the same root, 
and yet they sustain widely diflferent offices in the econo- 
my : one may contribute to the contraction of a muscle, 
while the other carries the mandate for its relaxation. 

We are warranted in believing, that even in a minute 
nerve, which appears a single cord, that a number of dis- 
tinct parallel filaments are lying side by side, enveloped 
in the same tissue, whose functions are widely diflferent 
from each other. 

Of the nine pair of nerves from the brain, let us pursue 



ANATOMICAL CLASS BOOK. 167 

them to their ultimate destination, not, however, with the 
vain expectation of ascertaining how it is that they exert 
an influence, but simply to contemplate the broad chart of 
sympathies which is thus spread for distributing and con- 
trolling that vitality which is so essential to order, to con- 
sciousness and to physical perfectibility. 

First — the olfactory nerves, taking their rise in the 
brain, having gone but little way within the skull, arrive 
at the top of the nose, where they suddenly divide into in- 
numerable hair drawn threads, which are lost in the lining 
membrane of the nose. 

The second, are the opt\c — expanding, when they 
have penetrated the globe of the eye, through the back 
side, into a thin web — properly named the retina, which 
is the seat of vision. 

In this instance, arising from the same substance as 
the olfactory to all human appearance, is a nerve whicli 
can only be influenced by the presence of light. 

When the nervous system is agitated by disease, even 
in the darkest apartment, the participation which the 
optic nerve has with the diseased action of the whole, pro- 
duces the sensation of vision, and nothing else. If it can- 
not be the bearer of this one item of intelligence, it can 
do nothing at all. If another sensation is to be conducted 
to the mind, — even if it relates to a moat on the face of 
the eye, another set of nerves, entirely independent of the 
optic, must be the bearers. There is no property in com- 
mon ; no relationship allowing the one to perform the func- 
tions of the other; yet they both seem to possess the same 
general structure, the same component parts, and have an 
origin from the same fountain-head, and depend for their 
vitality upon the same circulation. 

The third nerve is generally distributed to the muscles 
of the eye, to give guidance to several of them. 

Further — the fourth nerve, arising from the brain, 



168 ANATOMICAL CLASS BOOK. 

long, slender, and hair-like, is dispensed altogether upon 
one muscle, the one which rolls the eye downward towards 
the shoulder. 

The fifth nerve is the most intricate to understand. 
Lying almost in contact with the great artery of the brain, 
in the base of the skull, the single cord spreads itself out 
into the form of a reddish, fleshy pad, from which three 
distinct cords, all distinguished for their size have an 
origin. One of the three darts towards the eye, where it 
commingles with those we have been describing. The 
second branch, creeps through an orifice, and having 
reached the back part of the upper jaw, sends on a lash 
of fine lines, which find an entrance into the substance of 
the bones, and there furnishes the root of each tooth with 
one of them. 

Fig. 68. 




Explanations of Fig. 68. 
This plato will give some general idea of the intricacy of the 
nerves about the face ; the most difficult part of the neurology of the 
head is concealed by the bones, thou<rh we have adverted to the in- 
dividual nerves, which have their origin in the brain. 



B. (The 

C. <The 

D. (The 



ANATOMICAL CLASS BOOK. 16^ 

2. The optic nerve, nerve of vision, second in the order. 

3. Motor oculi, or third pair, arising from the brain. 

4. Trochlearis, fourth pan\ 

5. Trigeniini, with its three great branches, spoken of in the text. 
A. First division of the 5th nerve, called the opthalmic hranchi 

which divides again into — 
le Frontal nerve. 
:ie Lachrymal nerve. 
Nasal nerve. 

E. Second division of the fifth nerve. 

F. That branch of it going to the teeth and skin of the upper jaw. 

G. A ganglion. 

H. Branches going to the palate and throat. 
I. Video 71 nerve. 

6. Sixth nerve of the brain. 

K. Orio^in of the Great SympatJietic JVerve, spoken of in the text, 

L. Its additional organ, from the Videan nerve. 

M. Superior or first ganglion of the S3'mpathetic nerve. 

N. Third division of the fifth nerve. 

0. First division of the third bianch of the fifth nerve, going to the 
tongue ; this nerve is the organ of taste. 

P. A branch of the Gustatory, or tasting nerve, going to the ear 
and crossing the drum. 

Q. That division of the fifth nerve, which supplies the teeth of the 
under jaw, and finally comes out on the chin, to supply the muscles 
of expression. 

7. Seventh pair of nerves from the brain, or auditory, being the 
nerve of hearing. 

Perhaps, with all our care, the reader will scarcely understand 
the schcjue which has here been presented. It is not our object to 
be so minute as to weary, and yet we desire to be sufficiently par- 
ticular to be useful. 

The third branch makes its way out of the head, and 
directs its course to the inner side of the angle of the under 
jaw, where it enters a smooth canal, and in like manner 
furnishes each of the fangs of the under teeth ^^ ith a mi" 
nute nerve. 

A recollection of the origin of the dental nerves, will 
explain the reason w^hy a sound tooth, in the opposite jaw, 
sympathizes with the pain of a diseased one. 

To the eye again the S2?ctji nerve goes. Such a liberal 
supply of nervous influence as is thus given to this one 
organ, argues very clearly its importance. In no other 
portion of the machine is there a parallel distribution of 
nerves. 

15 



170 ANATOMICAL CLASS BOOK. , 

The seventh is a double nerve : — two cords, quite in 
contact, the one hard and the other soft, strike the extremity 
of that portion of the temporal bone, within the skull, con- 
taining the beautiful apparatus of the ear. One of them 
is expended upon the inside, and is the acoustic nerve : 
the other pays no regard to the ear, but, working through 
the solid bones, shows itself on the cheek, very near the 
middle of the external ear. 

What circumstance of organization prepares these 
nerves, arising, if not at the same point, at least from the 
same mass, for performing such opposite functions, as 
hearing and feeling, must long remain an inexplicable 
paradox. 

Still further in the series, comes the eighth pair, or par 
vagum — sliding out at the base of the skull, in company 
with the internal jugular vein. Coursing down the side 
of the neck, it dips into the chest, running through its 
whole extent, and finally shows itself in the cavity of the 
abdomen. From its first exit from the brain, it drops off 
twig after twig, nearly at right angles, for the superficial 
muscles on the throat, and the vocal tube ; to the larynx ; 
to the wind-pipe ; the lobes of the lungs on either side ; 
to the heart ; the great blood-vessel of the body ; to 
the stomach, liver, spleen, kidneys ; and to all appear- 
ance, neglects no viscera in any of the great cavities. No 
other nerve, but the sympathetic, seems to have such exten- 
sive relations, nor is any one of more consequence to or- 
ganic life. 

Reflect, for a moment, on the extraordinary offices of this 
one nerve. Both vessels and muscles on its first appear- 
ance, mutually depend upon its influence. Next, a class 
of involuntary muscles within the vocal box, cannot be 
varied in their contractions without its presence. Even 
the vibration of the vocal cords, the instruments of voice, 
would be unserviceable without it : the lungs would faul- 



ANATOMICAL CLASS BOOK. ]71 

ter — the stomach become idle — the liver rebel — the 
intestinal mechanism stop — and a universal failure of 
all the vital apparatus would inevitably ensue. 

One more — the ninth — the Imoual nerve, closes the 
series from the brain. Without it there would be no 
ability for moving the tongue. 

Let us re-examine the scheme of the nerves arising 
from the spinal marrow. 

That prolongation of the brain, which lies in the canal 
of the spine, gives out two sets of nerves, as from the two 
sides of the brain, but vastly larger in size. Besides be- 
ing large, several of them unite together, so closely, that 
it is really difficult to separate them, for the purpose, it is 
supposed, of establishing a wide circle of sympathies, and 
a combination of influence upon the muscles. Notwith- 
standing the apparent confusion, the most exact order is 
maintained. 

No man has been competent to an explanation of this 
complex mechanism. Though emanating from a condens- 
ed part of the brain, in which the intellectual operations 
are not admitted to be in force, a class of nerves have an 
origin, which are under the most complete subjection to 
another portion of the same substance. So it is in re- 
spect to all the dorsal, lumbar and sacral nerves. 



172 



AJNATOMICAL CLASS BOOK. 



Fig. 69. 




Explanations of Fig, 69. 
This plan shows the distribution of some of the nerves of the arm. 
a a. The cephalic vein, running between the pectoralis major and 
deltoid muscle. 

h. The basilic vein. 

c. The vena mediana longa, sending off. 

d. The median basilic vein. 

e. The median cephalic vein. 

/. The internal cutaneous nerve. 

g. The external muscular cutaneous nerve. 

h. A lymphatic gland. 

i. The fasica covering the muscles of the upper arm. 

k. The pectoralis major. 

I. The deltoid muscle. 



These considerations are curious in themselves, and in 
the mechanic, the scholar, and the philosopher, excite an 
ardent desire to comprehend the reason for the one, and 
the cause of the other. All the boasted and lofty preten- 
sions of philosophy are inadequate to the solution of these 
problems in the laws of the animal economy. 



ANATOMKJAL CLASS BOOK. 173 

GREAT SYMPATHETIC NERVE. 

As a point of union between the nerves of the brain 
and those of the spinal marrow, — to maintain a sympathy 
of connexion between the voluntary and involuntary or- 
gans, is interposed the sympathetic nerve^ which traverses 
the whole extent of the chest and abdomen, sending fibres 
in all directions, to every viscus in the body. Thus, by 
this one nerve, a mutual dependence is preserved among 
all the various portions of the living system. 

Nerves are certainly the organs of our senses. How, 
by the application of bodies to the different parts, a sensa- 
tion is produced, will never, we fear, be clearly explained, 
nor can we account, for a corresponding change in the 
brain, to produce an idea. Neither is it known how sen- 
sation is conveyed by the nerves to the brain. 

Sensation is a property peculiar to the nervous fibre, as 
irritability is to the muscle. 



15* 



174 ANATOMICAL CLASS BOOK. 



QUESTIONS. 



Is the brain a solid mass, within the skull ? 
How is it divided ? 

What are the hemispheres of the brain ? 
What do you understand by the lobes of the brain ? 
How many coats, or coverings has the brain ? 
Where is the little brain or cerebellum found ? 
Where is the spinal marrow ? 
What is the use of the spinal marrow ? 
Where do the nerves of sense arise ? 
How many nerves arise from the brain ? 
How are the nerves protected ? 
How many nerves arise from the spinal marrow ? 
How are they classified ? 

How are external sensations conveyed to the brain ? 
Where is the optic nerve found? 
Where are the olfactory nerves ? 
Are there cavities in the substance of the brain ? 
What are the cavities called ? 
What is the supposed use of those cavities ? 
What is the consequence of dividing a nerve ? 
Which is the seat of intellect, the large or small brain ? 
Can the brain be wounded with impunity ? 
How does the sympathetic differ from other nerves ? 
What is neurology ? 

Is there a correspondence in the structure of the brain and 
nerve ? 



ANATOiMICAL CLASS BOOK. 175 



THE SENSES. - 

The senses are divided into infei^nal ^nd exterjial. The 
internal are ideas, which the mind forms — -and may be 
produced by the agency of the external senses, or other- 
wise excited, as memory, imagination, conscience, and the 
passions. 

EXTERNAL SENSES. 

Hearing, Seeing, Feeling, Smelling, and Tasting. 
THE EAR. 

The ear, that organ by which we are made sensible of 
the impression of sound, is a very complicated instrument, 
and a beautiful piece of mechanism. 

It is a curious circumstance in the economy of organized 
beings, that the central portion of the human ear, termed 
the saculus vestibuU, hereafter to be described, is the basis 
of the apparatus of hearing in all animals, with the excep- 
tion of insects, but becoming more and more complex as 
inferior grades approximate the physical perfectability of 
man. 

Sound being a vibratory motion of the air, first put in 
motion by a solid body, is collected by the ear, as the pul- 



176 ANATOMICAL CLASS BOOK. 

sations travel onward, and transmitted directly to the au- 
ditory nerve. "^ 

Those beings only, which are denominated locomotive, 
having the power of moving themselves from one place to 
another, have an ear. Without this sense, of such vast 
importance to man, inferior tribes would be constantly ex- 
posed to dangers and even destruction. Nature has not 
been neglectful in granting the necessary means of hap- 
piness to every being, in proportion to its wants in the 
sphere in which it is destined to live; nor partial to man, 
in the development of all his senses, to the exclusion of 
other animals, whose physical propensities, necessities and 
circumstances are of as much importance to them, in the 
scale of existence, as his own. 



That appendage termed aiuHcuIay pinna or external ear, 
divested of the skin, is a thin, delicate piece of cartilage, 
quite elastic, and bearing some resemblance, in this re- 
spect, to parchment. On its outer surface, it is concave, 
but thrown into deep semicircular grooves, which termi- 
nate in one large dish, surrounding the canal that enters 
the bones, called concha^ because it resembles a shell. 
The lines or eminences, lying between the furrows, have 
definite names, as helix, antihelix, tragus and antitragus, 
and lastly, the fat pendulous portion, on the under edge of 
the ear, — in which trinkets are worn, in civilized society, 
in humble imitation of genuine savage life, — the lohus. 

* The antenna? of insects are considered the only organs that con- 
vey a sensation analogous to hearing. By the vibrations communi- 
caied to the body, thiough these, they are probably made suscepti- 
ble of simple sonorous impressions. 

* So called from awa, air. 



ANATOMICAL CLASS BOOK 



177 



Fig. 70. 




Explanations of Fig. 70. 

This is a well marked ear ot 
a man, drawn from life, 
a to e — The helix, forming 

the rim. 
a — The upper end or com- 
mencement of the rim, slop- 
ing into the conclia. 
5 — Part of the edge lost in 

the face. 
c, d — Prominent from the 

head. 
€ — The fold terminating in 

the lobule of the ear. 
/ to m — The antihelix. 
f,g — The upper end divid- 
ed into two ridges, — h the 
union of them, — /and^. 
i, k — lower end of the anti- 
helix, continued at i into 
the concha, and at k into 
the antitragus. 

I — The tragus covering the entrance to the ear — like a post at 
the corner of a street, to prevent sudden injury. 
m — Antitragus, 

n — Lohe of the ear, usually bored. 
0, o — Furrow between the helix and antihelix. 
p — The boat like depression between the lines of the antihelix. 
X — The concha. 
r — The beginning of the meatus auditorious, or canal. 



MUSCLES. 

Although in the human species there are muscles which 
seem at first siorht to have been desio^ned for movinoj the 
ear in different directions, their office is expressly to keep 
it tense, — equally on the stretch at all points, to increase 
its vibratory property. Occasionally, individuals are seen 
who have such development of the muscles, as to be able 
to move their ears at pleasure. Wags and buffoons are 
sometimes expert in the exercise. There are three of 
these muscles. 



178 



ANATOMICAL CLASS BOOK. 

FiiT. 71. 




Explanations of Fig. TL 

In this plate is represented the muscles peculiar to the external 
ear. «, d, e, the cartilage of the ear, as seen on that side looking 
towards the head. 

The attolens aurem,or lifter up of the ear, marked ?, 7n, shows 
where it becomes tendinous on the bones of the head, o, p, attach- 
ed to prominences 

g to t the anterior auris, placed between the face and ear. q, r. 
the poi'tion of it connected to the muscle of the forehead, growing 
narrower at s, and inserted into (he helix at t. 

II, z Two muscles, or rather, two portions of one, retrahentes au- 
rum, (0 draw the ear hack from the face. 

u, V, w,x, The upper or larger portion, consisting of fleshy 
fibres, u, v, w. 

y, Zj The inferior portion of the same muscle. 

All such animals as keep their ears habitually erect, as 
the fox, lynx, cat, horse, ox, ass, and various species of 
the dog, maintain them in that position by the strength of 
the muscles, which are under the control of the will. 

It is necessary for safety on the one hand, or success in 
seizing prey, by surprise, on the other, for the animal to 
have a distinct auricular perception, accompanied by a 
nice sense of smell. By remaining perfectly quiet, the 
ears are directed to and fro, as circumstances may require, 



ANATOMICAL CLASS BOOK. 179 

to receive, most favorably and forcibly the sonorous rays, — 
without being obliged to move the head.* Elephants, 
hounds, besides an almost endless catalogue of mammalia, 
have pendulous ears, as though the design was to defend 
the orifice ; — in these examples, the muscles are small, as 
they are in man. 

Birds have but a slight rim, approaching in outline, the 
pinna : lizards, of which there are about forty varieties, 
serpents and other reptiles, have nothing externally re- 
sembling an ear : in some, it is difficult, on close examin- 
ation, to discover the precise spot where the ear is located. 
Fishes are also destitute of an external organ ; and yet ail 
these families, including the amphibious, as frogs, turtles 
and the like, have a beautifully constructed internal ear, as 
remarkable, so far as a mechanical arrangement of parts is 
concerned, in conveying the pulsation of sound, as that 
of the most favored musician. 

EAR TUBE.f 

When the temporal or side bone of the head, contain- 
ing, entirely, the internal ear, is carefully sawed in twain, 
the canal, of which we are speaking, will be found about 
three quarters of an inch in length, and somewhat con- 
tracted towards its inner extremity — and, on an average, 
a little less than a quarter of an inch in diameter. This 
passage is a gentle curve, as the tube, from the external 
opening, rises upward ; but at half its length, turns down- 
ward again, and there bulges out in shape, something like 

* It is a favorite opinion of tlie author, that an ear trumpet for deaf 
people, instead of being hke the funnel of a common bugle, should 
have a broad plate, grooved, and indeed, v^^rought in exact imitation 
of the external human ear, it being certain that this is the best mode 
of directing sound into the head, or nature would have constructed 
|t difierenlly, 

t in books, termed the Meatus auditorius externus, — simply 
meaning the external passage to the inner cavities. 



180 ANATOMICAL CLASS BOOK. 

the bowl of a spoon. A delicate rim, like a moulding, 
rises on the edge of this expanded mouth, for sustaining 
the drum head, soon to be noticed, very much like the 
method of nailing a hoop within the mouth of a barrel, 
near the chime, to keep the head from falling in. To af- 
ford greater surface, that the drum head may be consider- 
ably larger than the extremity of the tube would allow, 
were it stretched perpendicularly across, it is sloped, so 
that it requires an oval cover, under such circumstances, 
very much larger than if it were round, and fitted to the 
square end of the pipe. All this may be examined in the 
temporal bone of a horse, sheep or dog's skull, as they are 
found bleaching in the fields. In these animals the re- 
semblance to the human ear is particularly striking. The 
common skin of the face is carried within the tube, for its 
lining, but perforated in numerous places, by the ducts of 
delicate little bags, lying between the bone and skin, which 
are constantly secreting and pouring out a bitter, nause* 
ous wax. The object of this excretion is twofold, viz. 
first, to keep the lining moist and pliable ; and secondly, 
to kill insects that may intrude there.* Crossing this canal 
from the sides, are strong short hairs, intersecting each 
other in such a manner, that an insect must overcome the 
resistance of those pikes, or chevaux de frise, in case the 
wax t does not arrest its progress, before reaching the 

*Ear wax is certain death to insects that feed upon it; though its 
composition is such, that they cannot restrain their appetites when 
peBt up where it is. Naturalists Iiave taken a hint from this, to 
prevent the depredations of vermin on dried preparations in cabinets, 
by washinai; them in decoctions of aloes or other vegetable bitters. 

f At birth the tube is liHed with a thick mucus, which, in some 
children, unless speedily removed, forms a cake of hard wax, com- 
pletely closing it ; and by the time the articulative organs are devel- 
oped, the child is actually deaf and dumb. There seenis to be a 
peculiar predisposition to this in some families. In others, children 
after liavingonce talked, lose their hearing at four or five j^ears of 
age, and become peimanently deaf and dumb. 



ANATOMICAL CLASS BOOK. 



181 



drum head, where its peregrinations are impassably lim- 
ited.* 

Fig. 72. 

Explanation of Fig. 72. 
This has been an exceedingly 
difficult plan to execute, so as to 
give the exact relation of parts ; 
hence it is very much foreshort- 
ened. 

c to ^, — cc, the meatus exter- 
nuSj as it appears, taken from 
the bone ; b, c, its two cur- 
vatures ; — the first e; the 
second c: — c?<i, the oblique slant, 
like a spoon bowl, at the in- 
ner end, cover(>d by the drum 
/leac/, spoken of in the text. 

e — The membrana tympani, 
stretched on its bony hoop, bulg- 
ing inward. 

The remaining parts, beyond 
the boundary ot the membrane, 
remain to be described, although represented here for the sake of 
keeping up the connexion of parts in the mind. 

f, g,h^ — The malleus ; f its handle; ^ its long handle; h the 
head or bulb. 

t, /c, — inchus, or anvil ; i short, and k, long processes, m stapes. 
V, H, A, m, n, jt?, — The labyrinth ; n, p, the cochlea, n, the be- 
ginning, p, termination, m, the vestibulum.f 




* When the glands are diseased in consequence of a chronic in- 
flammation, a thin, purulent discharge takes place, giving the indi- 
vidual, in some instances, trouble, inconvenience, and pain through 
life. I have seen a skull, in which the entire tube, on one side was 
closed up by a deposition of bone. The opposite ear was partially 
diseased in the same manner, but the peculiar circumstances of the 
case, while the person was alive, could not be ascertained. 

t I have found considerable difficulty in demonstrating this organ, 
without very large models : — one now in my cabinet, made of wood, 
magnifies the internal ear three feet, which can be seen and under- 
stood at a distance in a large hall. Formerly, when I taught anato- 
my in a Medical Institution, it was customary to suppose the col- 
lege an ear, and thus illustrate its intricacies by constant reference 
to the apartments and passage ways of that edifice. Instructors will 
derive great advant?ge from a similar course — by considering the 
school house, when explainhig the organ to their pupils, — the in- 
ternal ear, and the front door the drum. 



16 



182 ANATOMICAL CLASS BOOK. 

THE DRUM, OR MEMBRANA TYMPANI.* 

From the foregoing description of the canal, the exact 
locality of the drum head will be understood. Fitted to 
the rim of bone, in a manner similar to the parchment 
over the barrel of a snare drum, — it is kept perfectly tense, 
but by an arrangement of the fibres peculiar to its organ- 
ization. It is oval, and somewhat concave outwardly, and 
so transparent, that objects can be seen through it, being 
of the color of white oiled paper ; any person of common 
ingenuity, can dissect this beautiful membrane in the head 
of a dead fowl, with the point of a knife. It then presents 
a striking resemblance to a battledoor. This closes up 
the extremity of the tube, in a healthy ear ; notwithstand- 
ing, it is frequently ruptured by the firing of heavy guns, 
inflammation, and other accidents, without producing deaf- 
ness. Across this drum, a fine thread of a nerve is drawn, 
called corda tympani, which gives it the requisite sensi- 
bility and connexion with the system. When a pin-head 
is introduced far enough to touch the drum head, an ex- 
quisitely acute pain is the consequence, from pressing this 
nerve. 

We have seen men with the membranes ruptured on 
both sides, which was inferred from the fact, that in smok- 
ing, they puffed the fumes, for amusement, out at their 
ears; — yet the sense of hearing, did not appear impaired. 
The rationale of this will be subsequently explained. The 
deafness of old people might in some instances be allevi- 
ated by puncturing the membrane, which, by age, has 
become thickened and inelastic. 

* Lobsters, crabs, and, in fact, all that remarkable class of animals, 
whose skeletons are outside of the body, in the form of a shell, have 
their ears placed at the extremities of projecting points. The lob- 
ster's can be detected at the end of a short stump, near the root of 
the long feelers ; — it consists of a perforated bony stump, having a 
membrane stretched over it, — covering a drop of fluid, in which 
floats the auditory nerve. 



ANATOMICAL CLASS BOOK. 163 

No one can be in doubt as respects the office of this 
membrane : it receives the sonorous rays — having a broad 
surface, and being on the stretch, is put in vibratory mo- 
tion by the slightest pulsations in the air, — which it 
transmits to the still more important apparatus within. 

We have remarked that reptiles and fishes have no dis- 
cernible external orifice : — the external surface appears 
smooth, as though they were destitute of this sense. Un- 
der the skin, however, and in the bone answ^ering to the 
temporal one in man, there is a round hole, — growing 
larger within. This cavity is the tympanum or drum bar- 
rel — answering to the apartment beyond the drum head, 
in men and quadrupeds. The common skin which is thus 
drawn over the mouth of the tympanum, acts precisely as 
the drum head does, — vibrating to the least noise, with 
exceeding nicety. In the economy of reptiles — those 
scavengers of the earth, created to wallow in filth — at 
the threshold of organic life, an external opening would be 
soon destroyed, by being filled with mud, gravel or insects. 
The skin over the frog's ear and the camelion is very 
dense, shining and tremulous. Frogs, particularly, have 
a splendid circular piece of skin over the tympanum, just 
back of their large prominent eyes. There is a necessi- 
ty for uncommon delicacy, in their case, as their ear is 
constructed for hearing with equal precision in w^ater as 
well as air.* 

^ In that class of serpents which are covered with scales, the ex- 
ternal contrivance of a tense skin over the internal ear, is far infe- 
rior to the frog or lizard's: — to the underside of a cluster of thin 
scales, wedged in the loose skin, a slender bone, in figure like the 
pestle of a mortar, runs into the tube, towards the brain, and plays 
into the fenestra ovalis. 

All the variety of serpents are distinguished for their delicacy 
in the perception of sound. The hoa family, particularly, aj-e 
those which exhibit the most satistaction in music. The writer 
has carefully examined a hoa constrictor ^ which when fully grown, 
is horrible to the sight, that was inattentive to sounds, except when 
hungry. At such times, the scratch of a pin against the wall. 



184 ANATOMICAL CLASS BOOK. 

INTERNAL EAR. 

All parts beyond the drum-head, are collectively called 
the labyrinth^ in consequence, probably, of their intri- 
cacy. 

To understand the arrangement of the apartments to 
which the reader is now to be introduced, requires pa- 
tience, as well as close observation, or the mechanism 
cannot be comprehended. First the 

DRUM-BARREL, OR TYMPANUM. 

Directly behind the membrane is a small room, of the ca- 
pacity of M common white bean. Its name is derived from a 
word, meaning a drum, as it is one in office, but having, 
instead of one head like the kettle or two as in the snare 
drum, it has three heads;— the largest of which is 
towards the outer ear, — while at the other end of the 
barrel, are two little ones. 

Three distinct apartments, one beyond the other, which 
in anatomical works, have further minute subdivisions, 
collectively make up the labyrinth. First, the tympanum^ 
just adverted to ; secondly, the vestibule ; and thirdly, the 
cochlea. In connexion with these are certain tubes, hav- 
ing sundry barbarous, unintelligible names. 

Behind the ear, a hard knob of bone may be felt, with 
the finger, (mastoid process) on which that muscle is fast- 
ened, which, with its fellow on the opposite side, brings 
the head forward ; within, it is hollow — being full of con- 

loused the monster to unceasing watchfulness. The ear of the land 
tortoise, and the rattlesnake, do not differ as much as the physiolo- 
gist might at first suppose — though in the water turtle, constituted 
for hearing alternately in air and water, there is a perceptible differ- 
ence. In the first a single bone is found ; while in the latter, in 
addition to the bone, there are fine chalky particles, which move 
ao-ainst each other, to propagate the motion or noise in the water, to 
the ramifications of the nerve. 



ANATOMICAL CLASS BOOK. 185 

ical cells resembling the spokes of a wheel, growing small- 
er as they unite in one pipe, which opens into the drum 
barrel. Physiologists agree that the use of these cells is 
for reverberating sound, that it may gain strength by being 
reflected from wall to wall, in order to excite a stronger 
sensation when conveyed to the nerve : these are partic- 
ularly large in some animals.* A similar piece of me- 
chanism is discoverable in the cheek bones, and even the 
centre bone of the skull, for reverberating and strengthen- 
ing the voice. Lions have large cavities in the bones of 
their heads and faces, on purpose to increase the intensity 
of the vibrations ; -— hence their characteristic roar. 

In another direction, is the minute orifice of a cone- 
shaped pipe, eustachian tube^ that opens with a trumpet- 
like extremity in the mouth, — it being necessary to the 
free vibration of the drum head, that the same quality of 
air that transmits the sonorous pulsations, should also exist 
on the opposite side, within the barrel : the use of the 
eustachian tithe, (so called from Eustachias, the discover- 
er) is to admit it. Nothing, therefore, is more completely 
an imitation of the tympanum of the ear, than the martial 
drum, which has a little hole in the side, equivalent to this 
we are describing, descending to the mouth, the nearest 
point from which atmospheric air could be taken, without 
disarranging or disturbing the functions of other organs. 
By closing the sounding hole of the drum, the music is 
less audible — sounding, when the air inside becomes rare- 
fied, like music in a well. The reason is, the equal bal- 
ance of air is destroyed : — such is the object and office 

* In a letter from the venerable Dr James Thatcher, of Ply- 
mouth, the following curious fact is related: 

' Reflection of Sound. — A gentleman told me, to-day, (May 3d, 
1831,) that a few days since, he was passing through one of our 
streets where there were considerable intervals between the houses, 
a gentleman totally blind, walking with him, assured him that he 
knew exactly when he vras passing a building, by a peculiar sensa- 
tion in his ears, occasioned by a different concussion of the air.' 

16* 



186 ANATOMICAL CLASS BOOK. 

of the eustachian tube. Sometimes, in violent sneezing, 
or sudden cough, the patulous mouths get stopped for an 
instant with saliva ; and many readers are probably famil- 
iar with the sensation of fulness that ensues, — giddiness 
and ringing in the ears, to the annihilation of accurate 
auricular perceptions, till the cause is removed.* 

There are many existing cases of deafness, having their 
origin in some such cause : the pipe finally inflames, and 
becomes permanently sealed : a skilful aurist, under such 
circumstances, will adroitly puncture the drum head, with 
an instrument purposly constructed, and relieve the patient 
without pain. 

OVAL WINDOW, OR FENESTRA OVALIS. 

Fenestra ovalis means an oval window, covered by one 
of the two little drum heads. Beyond this, supposing a 
person could pass through, he would arrive in the vestibule, 
or second room. Lower down, but a few lines from this, 
is the second little parchment head, called 

ROUND WINDOW, OR FENESTRA ROTUNDA. 

This is a round window ; were it possible to tear it 
away and creep through the frame, the traveller would 
enter into one of the canals of the cochlea. 

* Notwithstanding the fine arguments of writers to the contrary, I 
believe that partially deaf persons hear better when the mouth is 
open ; instinctively, it may be observed, such individuals listen with 
an open mouth. The pulsations of sound thus enter the tympanum 
and set the fenestra ovalis vibrating, — but very much less forcibly 
than through the external opening, in its healthful condition. 



ANATOMICAL CLASS BOOK. 

Fiff. 73. 



187 




Explanation of Fig. 73. 

In this diagram, the labyrinth and little boiies of the ear, are mag- 
nified exceedingly. This is to show the manner in which they are 
connected, and the order in which they are placed. 

a to e — The jnalleus, about to be described; a, a long process ; 
b, a shorter one ; c, the handle, attached to the drum head ; d, the 
neck; and e the head of the malleus, like a mallet. 

/to i — The inchus ;fits body : g its short leg ; i the point united 
to the stapes. 

kton — The stapes; k its small head, i the anterior leg, n the 
basis connected with the membrane which closes the fenestra ovalis. 

to ?n — The labyrinth ; o,r, the first turn ot the cochlea ; s, t, u, 
V, the second ; w^ x, the half or third turn ; y the foramen rotun- 
dum or round window ; zz, the vestibulum ; A B C D, superior 
semicircular canals; A, the ampulla; B C, its curvature; D, its 
union with the inferior or posterior canal ; E F G H, inferior canal; 
E, its ampulla ; F G H, its curious curve and its junction with the 
first; I K L M, the exterior canal; I, the ampulla ; K L, the direc- 
tion of its curve ; M, its termination in the vestibule. 



188 



ANATOMICAL CLASS BOOK. 
Fig. 74. 




Explanation of Fig. 74. 

In this, the bony case of the labyrinth, has had one half cut away 
to exhibit the interior. 

d to I — The upper part of the cochlea; aa, the thickness of its 
external shell in a foetus of eight months ; b c d, the lamina spiralis ; 
be, scala vestibuli; e f gh i, the scala tympani. Here is seen 
the bony lamina spiralis; 6 its origin; d its termination in a little 
hook, termed hamulus ; k the opening of the infundibuluin, where 
the scalae communicate ; I the opening of the aqueduct, or drain of 
the fluids from the cochlea. 

m to g — The under half of the vestibulum; m the thickness of 
its case in the foetus ; n the fovea or round pit ; o an oval pit ; ;? a 
ridge between them ; q opening, of the aquaeductus vestibuli. 

r\ g, k,l, — The canals divided; r the thickness of their case in 
the infant ; g the posterior ; / exterior semicircular canal; 1 opening 
of the big end of the posterior canal ; 2 opening of the large end of 
the superior ; 3 the opening common to their united tubes ; 4 the 
larger end ; 5 the contracted opening of the external canal. 



LITTLE BONES OF THE EAR, OR OSSICULA AUDITUS. 

Perhaps there is no insulated portion of an animal, that 
more clearly and satisfactorily evinces superhuman design, 



ANATOMICAL CLASS BOOK. 



189 



than the figure and articulation of the four ear bones, 
which we shall now endeavor to describe. The technical 
phrase ossicula audituSy in the Latin, implies little bones of 
the ear. They are by far the smallest in the body. The 
first, in the order of their distribution, is the malleus or 
mallet, — having a faint resemblance to that instrument, 
inasmuch as there is a long handle joined to a round knob. 
Secondly, the inchus, from its resemblance to an anvil : — 
OS orbiculare or round bone, the least in size that has ever 
been drscovered, — being in man considerably smaller 
than a mustard seed. And lastly, the stapes — or stirrup, 
almost a miniature fac simile of a saddle stirrup. Birds 
have but two of these, of which the malleus is meet devel- 
oped. Turtles have but one, the malleus ; and reptiles, 
as far as personal dissection warrants, have but two. In 
these classes, there is a departure in form, from those we 
are contemplating in our own species. 

Fig. 75. 

Explanation of Fig. 
75. 

Here is presented a 
magnified view of the 
ear bones. The os or- 
biculare, or round bone, 
is not represented, be- 
ing considered by some 
as only an appendage 
of the malleus. 

The malleus known 
by its long arms; a, 6, 
c, d, e, mark the same 
points as in Figure 73. 
'1 he inchus, resem- 
bling a molar tooth, 
having shorter arms, is in the same position as in Figure 73 ; the let- 
ters have the same reference. The star points out the articulating 
surface for the malleus. 

Any person from the foregoing remarks, will recognise the stapes, 
by its shape — ab its head; c the neck; d anterior crus ; e the 
second ;/ the basis. 

The fourth drawing represents another view of the stapes, seen 
from above — a its cartilage ; b anterior ; c posterior ; d the basis. 




190 ANATOMICAL CLASS BOOK. 

As these bones are placed in the drum barrel, one 
joined to the extremity of the other, they make a compound 
lever, — the object of which is, to have the freest and long- 
est extent of motion, in a little space ; — unlike the muster 
drum, which is continually referred to on account of fa- 
miliar illustration, the sticks of this are fixed on the inside, 
and though no hands are there to beat them on the head, 
they are connected to little cords, which jerk them down 
with a sort of conscious independence, whenever there is 
the least noise abroad, to give the brain intelligence, as it 
were, of what is going on without.^ 



Fig. 76. 



H?^ 



Explanation of Fig, 76. 
In this drawing the little bones are represented 
of their natural size, with the exception of the last 
one, — which is magnified. 



There is some resemblance in the motion to be effected 
by this chain of bones, to the up and down motion of the 
hand at the extremity of the arm, viz. — carrying one end 

* There are some diseases familiar to medical gentlemen, besid^ 
local affections of the ear, which fix upon the bones about the face. 
Under such circumstances, a sanious discharge washes these little 
bones entirely away : — nothing is moie certain, than the fact, that 
the three first bones may be corroded and floated from their connex- 
ions: — indeed, extracted with forcep=i, and the patient hear, to all 
intents and purposes, nearly if not quite as well as he did before. 
Thus the memhrane, (drum head) and three out of four bones are 
unnecessary, it seems, in the auditory apparatus of man. Stripped 
thus, it falls below the fiog's — being deficient in an external cover- 
ing or vibrating membrane. The vibrations, in this case, act directly 
on the foot piece of the stapes, — which is broad enough to offer re- 
sistance to the vibrating air. Being connected with the membrane 
oilhQ fenestra ovaUs,ii produces a motion in it, which is propagated 
to the fluid beyond, and thus the nerve becomes agitated. If the 
stapes could be detached without rupturing the membrane of the 
fenestra ovalis, then hearing could be effected independent of the lit- 
tle bones. Their use is merely to strengthen the vibrations within, 
just in the proportion that they have a tendency to become feint, as 
the distance increases from whence they had their origin. 



ANATOxMICAL CLASS BOOK. 191 

of the lever through considerable space, while the other, 
to which the power is applied, has no perceptible motion, 

Small as the osicula auditus are, the first and last of the 
series have muscles, called tensors, laxators, &c, which 
are susceptible of demonstration. Rough points and pro- 
jections on the inside of the tympanum, give attachment 
both to the muscles and the bones themselves. Even 
these minute points, the old anatomists have belabored with 
what they supposed significant names. One end of the 
malleus, the handle, is connected with the inside of the 
membrana tympani ; the other is fitted into a socket of the 
inchus — and that articulated with the orbiculare or round 
bone, — which stands as a medium of connexion between 
the two. 

Such is the mechanical adaptation of one of these bones 
to the other, that if the extreme point of the handle of the 
malleus be moved the millionth or ten millionth part of 
an inch, by the vibrations of the drum head, it will so ope- 
rate on the inchus and that on the stapes, through the in- 
tervention of the orbiculare, that the last bone will move 
through treble the space, by a single sonorous pulsation of 
the malleus, in the same period of time. In fact, the 
stirrup, in plain language, is exactly fitted into the oval 
window, like the box of a pump, so that a motion given to 
the handle of the malleus, operates on the chain, to effect 
the stapes, that it may work backward and forward, with 
the same motion and on the same principle of the work- 
ing of the piston of a syringe. To hear, it is necessary 
that the stapes, attached to the parchment window, should 
move to and fro. 

ENTRY, OR VESTIBULE. 

This word implies an entry, •— being an intermediate 
apartnaent between the tympanum and cochlea ; in the 



192 ANATOMICAL CLASS BOOK. 

sense in which it is now received, it is a hall of the edi- 
fice beyond, — from which doors are opening into various 
winding passages. Its length and diameter are not far 
from those of a grain of wheat ; — as in a preceding para- 
graph, if we suppose an individual has torn away the stapes, 
stretched across the oval window, and then cut away the 
latter, to wend his way into the vestibule, he will find it a 
long but narrow room.* 

On one side he will discover three holes, and on the 
opposite, only two, which are the openings or communi- 
cation of the semicircular canals, with the vestibule. With- 
in this vestibule, are two sacs, water tight, containing a 
clear fluid. Though there is no communication between 
them, the quality of the fluids distending them, is alike 
— one is considerably larger than the other, and both 
together, w^ould not equal in bulk, two good sized pin- 
heads. The one of the greatest magnitude, is called the 
alveus communis or the union of rivers — from the circum- 
stance that the canals were thought to resemble streams 
of water, having a free communication with the water in 
the reservoir. Sacidus Cochlea^ the lesser one, though 
separated from the other by the thickness of its own and 
the other's wall, is eked out into along gyrating tube, that 
traverses the cochlea. 

This large sac, alveus communis^ is the elementary one 
found in polypi — and it is this that is built upon from one 

* If, by any circumstance, the membrane of the oval window or 
fenestra ovalis, is ruptured, the fluid of the labyrinth will certainly 
escape. This constitutes incurable deafness. No operation, no pre- 
scription can avail, as, in the constitution of things, the acoustic nerve 
cannot be acted upon in any other way, than through the agitation 
of tne fluid which surrounds it. Dr Darwin was of opinion that 
if a deaf person dreamed of hearing, the internal parts, essential to 
the function, were unimpaired. The same remark is applicable to 
the blind. I have invariably found that the incurably deaf as well as 
incurably blind, never dream of hearing or seeing. This clearly 
shows a destruction of the sense, inasmuch as the imagination cannot 
rouse a single vestige of their former activity. 



ANATOMICAL CLASS BOOK. 193 

species to another, till perfected in the complicated machi- 
nery of the human ear. 

Besides the sacs themselves, the porch is lined with a 
membrane of exquisite texture, in which is conducted 
the vessels that administer the blood to the contained 
reservoirs, and also secrete their contained fluid, aqua 
labyrintha or water of the labyrinth, further to be com- 
mented upon. 

SEMICIRCULAR CANALS. 

These are properly a prolongation of the vestibule — 
the design evidently being to furnish surface for expand- 
ing the auditory nerve, without carrying it onward towards 
organs that would be affected by their presence. No 
way could be devised, more strictly economical, than to 
have a circular or semicircular canal, — curving in a little 
space, as in a very small solid bit of bone. Precisely on 
this plan, are these canals — they are three in number. 
Let it be remembered in this place, that the tympanum 
including the vestibule, little bones and semicircular 
canals, exclusively make up the ear of fishes, and rep- 
tiles — neither of these tribes having an external ear, nor 
the cochlea, which still remains to be elucidated. 

So much is necessary to the perception of simple 
sounds : the cartilaginous fishes, (sharks, eels, &.c,) have 
the canals, and are therefore capable of judging of the 
direction and condition of different sounds. The Chinese 
drive fish from the crevices of rocks to the angling ground, 
by beating a gong. Pike and carp, reared in artificially 
stocked ponds, both in Poland and France, have been 
taught to come to a particular spot to feed, at the ringing 
of a bell. Serpents, abundant evidence substantiates, are 
exceedingly excited by the lively strains of rtiusic — coil- 
ing themselves into a variety of folds, and giving a tremu- 
17 



194 ANATOMICAL CLASS BOOK. 

lous vibration to the tail, which long experience proves to 
be the result of a pleasurable sensation, and not one of 
displeasure, rage or pain. 

Two of these canals, as they wind towards the side of 
the vestibule, coalesce — and when they perforate the 
wall, have only one orifice in common. The third enters 
alone, and this explains the two holes seen on one side of 
the vestibule ; on the opposite side are three, being the 
orifices of the same three canals, opening singly. When 
the semi-circular canals are closely examined, they are 
observed to be larger at one extremity, near the walls of 
the vestibule, than at the other ,• the bulbs or bulges are 
termed ampullulce or bottle shaped. A crook-neck squash 
is an exact, though greatly magnified representation of 
any one of the semicircular canals. The diameter of the 
circle, of which they are a little more than two thirds of a 
segment, varies but little from one quarter of an inch in 
man : but the calibre of the canals themselves will scarce- 
ly admit the introduction of a fine bristle. A probable 
reason for the swelling out of the ampullulae will be given 
when discoursing particularly of the nerve. 



ANATOxMICAL CLASS BOOK. 

Fig. 77. 



195 




Explanation of Fig, 77. 

In this enlarged diagram of the labyrinth which is laid open, the 
soft parts are seen. Young gentlemen pursuing medical studies, 
will derive the most profit from this plan. 

a io e — The lamina spiralis viewed from above. The distribu- 
tion of the nerve will not be easily distinguished I fear — a a a, the 
first turn ; b h, second turn \ c d e, the third turn of the lamina ; d e, 
where the scalse communicate. 

Comparetti has described the lamina to consist of four different 
substances, or zones : 1, the bony zone ; 2, coriaceous ; 8, vesicula ; 
4, the membraneous zone. 

/, sacculus sphericus ; g, space btween that and the alveus com- 
munis ; h, alveus communis ; 1 k i 3, posterior canal ; 1 z, its am- 
pulla ; A:, the nerve expanded over it ; 2 Z m, the superior canal ; I, 
the ampullulae ; 4 n 5, the exterior canal, communicating at both 
ends with the alveus communis. 

Within these bony tubes, are membraneous ones, — 
prolongations of the sacs found in the vestibule ; but they 
are not in contact with the walls : on the contrary, they 
are kept from them by the interposition of a fluid, whose 
equal pressure keeps them exactly in the centre. Further 
to show the exceedingly minute structure of this accurate- 



196 ANATOMICAL CLASS BOOK. 

ly operating instrument, it is necessary to remember that 
the membraneous tube is also distended with a transpa- 
rent watery liquor. Still smaller canals, running through 
the temporal bone in which the internal ear is located, 
pour in and discharge the old fluid, as an unceasing 
process. 

SNAEL-SHELL, OR COCHLEA. 

The third and last anatomical division of the internal 
ear, is the cochlea, or snail shell. Recollecting how the 
canal of a snail-shell winds about a central pillar, will 
enable the reader to understand the text. In the snail 
shell of the ear, however, there are two canals, side by 
side, which wind twice and a half round a central pillar, 
which is hollow, and termed modiolus. At the apex, the 
two canals open in one common cavity, but a thin slip of 
bone caps over both openings as well as over the top of the 
hollow end of the pillar, like a parasol. This is the cupola, 
in technical language. The upper end of the hollow 
pillar is broad, but becoming narrower, the lower is de- 
nominated the infundihulum or tunnel-shaped extremity. 

After leaving the inner extremity of the vestibule, com- 
mences one canal of the cochlea, which becomes smaller 
and smaller, till it terminates under the cupola. Now, 
supposing the reader were travelling in this canal, he 
could step from the termination of the one we are describ- 
ing, over the broad opening of the modiolus^ shaded above 
by the cupola, into the mouth of the second canal. By 
following its turns, increasing in diameter, as he proceeds, 
till he has gone twice and a half round the modiolus, he 
would arrive at the fenestra rotunda or round window. 
This being like parchment, semi-transparent, he could 
look into the tympanum where the little bones are lodged. 

Thus it is, that one canal is in reality a prolongation of 



ANATOMICAL CLASS BOOK, 197 

the vestibule, and the other opens into the tympanum. A 
fluid fills the canals, which is prevented from escaping by 
the oval window, in the vestibule, in one direction, and 
by the round one at the other. In the centre of this li- 
quor, floating, are the finely organized threads of the 
acoustic nerve. 

Those animals having the power of combining sounds 
to produce song, have a cochlea, and generally, a corres- 
ponding vocal apparatus. Birds, have a cochlea, but it 
consists only of two tapering tubes, united at one ex- 
tremity, but diverging at the other, as in man. A musical 
ear was once thought to depend exclusively on a cochlea; 
but common sense teaches us, and the fact is notorious, 
that singers as well as those who cannot sing, have ears 
constructed precisely alike ; and therefore, the whole 
mystery depends on the peculiar development of the brain. 



Explanation of Fig, 78. 
^(l^Ml^ Let it be remembered by tbe reader, that part of 

the hist as well as the following diagratn, which has 
sort of shell-like turn, is denominated the cochlea. 
The object of this drawino^, is to show the soft con- 
tents of the labyrinth, of their natural size and in their 
natural situation. All the eminences of the temporal 
bone have been broken away. 

a a, the spiral plate of the cochlea ; h, the round sac, or sac of the 
cochlea ; c, alveus communis; g*, the posterior ; /c, the superior, and 
/ the exterior semicircular canal. 



THE HEARING, OR AUDITORY NERVE. 

There is no part of the intricate organ we have been 
explaining, more absolutely difficult to display and to fully 
understand, in all its relations, than the nerve of hearing, 
and we shall therefore avoid all laborious descriptions, and 
merely generalize. 

The auditory nerve is the seventh, — a pair precisely 
alike on the two sides of the brain ; not much larger than 
17* 




198 ANATOMICAL CLASS BOOK. 

cotton sewing threads ; it enters the cochlea first through 
a sieve-like orifice, on one side of a bone that projects 
from the inside of the skull towards the brain. This de- 
pression where the nerve enters, towards the external ear, 
is the meatus miditorius internus. It assumes a variety of 
shapes in distributing itself in the various tubes, sacs, canals 
and pits we have been exhibiting. At some points, many 
delicate threads are discoverable, side by side : at others, 
fibres are seen floating in the surrounding fluid, from the 
main trunk : at others, the nerve assumes the form of a 
flocculent paste, and at others, a woolly texture. The 
whole, distributed thus elaborately, constitutes the nerve 
of hearing. 

The sense of hearing is not confined, in a healthful con- 
dition of the organ, to any one particular part or point : 
the sensation is perceived in the whole at the same instant 
of time. It has been recently demonstrated that the hu- 
man ear is so extremely sensible, as to be capable of ap- 
preciating sounds which arise from about 24,000 vibrations 
in a second ; and, consequently, that it can hear a sound 
which lasts only the 24,000th part of a second. The ques- 
tion now may arise, why was it necessary to construct 
such an intricate machine, if one part of it has not a high- 
er office to sustain than another ? 



ANATOMICAL CLASS BOOK. 
Fig. 79. 



199 




Explanation of Fig. 79. 

An enlarsjed view of the lahyrinth laid open. 

flj 5j c, —the cochlea. To exhibit the zona mollis, the outside or 
bony case is removed. 

d, €,f, — the vestibulam."" 

g^ to q, — the semicircular canals. 

g, h, ij — the posterior ; A', /, m, the superior; 0,^0, q^ the exterior 
canal. 

1, 2, 3 — the lamina spiralis, seen on its under surface ; 3, the two 
sacs so often mentioned in this work, in the vestibule, which, view- 
ed in this plan, look like one. 

/, M, — the membranous posterior canal. 

V ID, Xy — the superior membranous canal, uniting with the last, 
at X, y, z, the exterior membranous canal. 

This diagram exhibits the distribution of the acoustic nerve in the 
labyrinth ; the large branch goes to the cochlea, and the three oth- 
ers, smaller, to the vestibule, and three semicircular canals. 

Economy was the object : — to pack as much as possible 
in the smallest space, is observable in all animal mechan- 
ism. No other kind of arrangement of cells in the small 
block of bone in which these are found, would or could 
have afforded so much surface to spread out such an ex- 
tent of nerve. This then is the probable reason for semi- 
circular canals, the cochlea and their appendages. 



200 ANATOMICAL CLASS BOOK. 

MUSICAL EAR. 

No question oftener arises, on surveying the auditory 
apparatus, than this, viz. — why has one person an ear for 
music, when another, whose internal organ is as beauti- 
fully and nicely constructed, is totally unable to appreciate 
harmonious sounds ? The difficulty, probably is in the 
peculiar development of some portion of the brain, and 
therefore does not arise in consequence of a defect in the 
original conformation of the ear. It obviously requires 
as delicate auricular perception to appreciate, and imitate 
articulate sounds, as it does to sing in concert. It is by 
no means uncommon for an individual to cultivate the 
highest departments of instrumental music, and at the 
same time be wholly unable to sing. This is entirely 
owing to some defect of the vocal organs. A perfect or- 
ganization of both, in the same individual, united to that 
inscrutable condition of the brain which gives the taste 
for music, constitutes the most gifted performer, and such 
as Handel, Mozart, Beethoven, Mad. Catalina, Garcia, the 
wonderful Paganini, and a few others, have exhibited to 
the highest degree of human perfection. 

Another circumstance in relation to the musical ear, is 
the following : some persons have the ear as well as the 
taste for music, and yet find it impossible to accompany 
others in a performance. This arises, probably, in most 
cases, in consequence of a non-agreement in the tension 
of the drum-heads of the two ears, or a want of corres- 
pondence in the calibre of the internal tubes ; hence one 
ear perceives sounds (o be half a tone above or below the 
other : — the same occurs in respect to the focal distance, 
oftentimes, of the eyes. Time rarely corrects the former, 
though in the latter it finally modifies the aberration.* 

^Philosophers of antiquity were more conversant with the floctrine 
of sounds, than the moderns : the remarkable cavern, hewn in a solid 



ANATOMICAL CLASS BOOK. 201 



DISEASES OF THE EARS. 

A ringing in the ear is an indication of a diseased state 
of the nerve ; generally, it arises from some slight in- 
flammation. The beating of adjacent arteries, in conse- 
quence of inflammation in the throat, may excite the nerve, 
which being incapable of transmitting any sensation but 
that of sound, the ringing is an imperfect sensation. The 
eye, when the optic nerve is encroached upon by inflam- 
mation of surrounding parts, or the pressure of a growing 
tumor, transmits the sensation of light, though the indi- 
vidual be in total darkness ; affections of the brain itself 
may remotely excite a morbid action in many or all the 
nerves of sense. Hence, persons dying of acute inflam- 
matory diseases, complain of hearing loud and strange 
noises, although the apartment is perfectly still. 

EAR-ACHE. 

Very many individuals are subject to excruciating pain 
of the internal ear, on taking the slightest cold, or from 
exposing themselves to a humid atmosphere; and others 
seem to inherit the disease, which no application can re- 
move. A peculiar irritability of the nerve that crosses 
the drum-head, (corda tympani) may be one cause, — the 
vascular covering of which, suffering from a chronic in- 
flammation, compresses the nerve and thus produces al- 
most intolerable agony. Defending the external opening 
with cotton wool, or lint, is a common and rational de- 
fence ; but the introduction of oils, spirits and the like, is 
often attended with pernicious consequences. Generally 

rock by a celebrated tyrant, and called Dionysius^ ear, is said to have 
been an exact model of the windings of the human ear. Vitruvius 
gives an interesting account of the manner in which the Greeks con- 
trived to augment the compass of the voice in theatres, by placing 
large metal vases in different parts of those edifices. 



202 



ANATOMICAL CLASS BOOK. 



such cases end in deafness. Nature, to save the rest of 
the machine from becoming disordered, by its sympathy 
with the diseased member, finally destroys it, as firemen 
demolish contiguous buidings, to save a town, when they 
can no longer master a threatening conflagration.* 

PARTIAL DEAFNESS, FROM A COLD. 

Probably, in a majority of cases, partial deafness arises 
from a slight inflammation of the tube opening behind the 
palate. In consequence of this, the balance between the 
air in the tympanum and mouth, is destroyed, and the reg- 
ular vibratory function of the membrane is altered. A 
deafness in one ear generally depends on this cause. 
Deafness in fevers is an excellent symptom, and offers en- 
couragement in the worst cases, because it is an evidence 
of a diminution of the morbid condition of the brain. 

PERMANENT DEAFNESS. 

A total deafness implies a destruction of the organ : 
but we apprehend there are only a very few persons in this 
condition. Even in those unfortunate fellow-beings who 
are deaf and dumb, the faculty of hearing, to a certain ex- 
tent, still exists. They hear the report of a cannon, or 
heavy thunder, which act so powerfully on the body as to 

* Painful affections of the ear may be induced from habitually pick- 
ing the ears, — a very pernicious practice. In India, where a class of 
men follow the profession of cleansing ears, cutting the nails, &c — 
though in that climate the secretions may be fluid, in greater abund- 
ance, and discharge freely, the plucking of the hairs and frequent 
introduction of scraping instruments render the organ irritable, and 
less accurate in the perception of sounds. 

Tumors, ulcerations and other troubleome complaints are brought 
on by picking them. A sudden pressure on (he corda tympanic 
a nerve belonging to the face, which crosses the drum head, by the 
head of a pin, may forever after render it liable to inflame on the 
slightest exposure. 

Fluids ought not to be poured into the external ear to drown in- 
sects, as the worst consequences may ensue. 



ANATOMICAL CLASS BOOK. 203 

rouse the sleeping energies of the nerve. In fact, the tre- 
mor is communicated through the bones of the head. 
Fishes, of the bony kind, have the organ of hearing acted 
upon in the same manner, as the nerve is completely cased 
up in solid bone, without either drum-head or external 
openings. 

CONCLUSION. 

None of the organs of sense are more complicated or 
splendidly constructed than the one under consideration. 
The vi^ill has it but slightly under its control, and being 
unable * to withdraw itself from impressions ^^ it has the 
curious apparatus of little bones to increase or diminish 
the intensity of impressions, like a regulator between the 
external agent and the nervous cords. Judgment, by the 
combined assistance of the other senses, perfects the 
function of the organ — and ideas, without number, are 
constantly ushered into being by the sense of hearing. 

By this sense, music is a never failing source of plea- 
sure, heightened and infinitely modified, according to the 
physical development of the ear, and the discipline and 
education to which it has in modern times been subjected. 
The causes of the pleasure resulting from harmony and 
melody, are very far from being satisfactorily explained, 
notwithstanding the sagacious conjectures and repeated 
attempts of the most able metaphysicians, as well as phy- 
siologists : we know no more of them than we do of the 
causes of the pleasures and pains of all the other senses. 



204 ANATOMICAL CLASS BOOK. 



QUESTIONS 



Of what use is the external ear ? 
What is the tympanum ? 

How many bones are found in the internal ear ? 
What is the use of the drum ? 

Is there any communication between the mouth and inter- 
nal ear ? 
What is the vestibule ? 
What do you understand by the cochlea ? 
Is there a fluid in the vestibule ? 
What is the fenestra ovalis ? 
Where is the acoustic nerve placed ? 
What is the use of the little bones ? 
Can sound be heard without the stapes ? 
What are the semicircular canals for? 
Does a rupture of the drum destroy the sense of hearing ? 
Of what use is air in the tympanum? 
What constitutes a musical ear ? 
What produces permanent deafness ? 
Of what use are cells in the bone, near the tympanum ? 
Why do deaf persons hear better with the mouth open ? 
How does the internal ear of birds differ from man's ? 
Can a person hear without the external ear ? 
Why is pain produced by touching the drum ? 
What is the use of ear wax ? 
Of what use is the round window of the tympanum ? 



ANATOMICAL CL.\SS BOOK. 205 



THE EYE. 

No one has been able to explain hoiv or why we see. 
The visual organs are constructed with such exact refer- 
ence to the laws of light, that telescopes and microscopes, 
are but imitations and modifications of the apparatus of 
the human eye. There is a difference, however, between 
the animate and inanimate, the most wonderful and as- 
tonishing. The first is a perceiving instrument; the 
second, a receiving. 

All animals living on land, have their eyes very similar 
in structure. 

In carnivorous animals, the original principle of vision 
is preserved, but most curiously modified, according to 
their habits and characters. 

Those that live bv violence, have the pov/er of seeing 
in the dark. 

Fishes, by a further modification of the original appa- 
ratus, probably see distinctly in the darkest night. 

With another alteration, not unlike changing the dis- 
tances between the lenses of a spy-glass, another family, 
as seals, iS^c, see alternately in two elements. Still far- 
ther, on the descending scale of creation, insects are pro- 
vided with motionless eyes, — giving them the faculty 
of seeing in every possible direction. And, lastly, in 
snails and some kinds of worms, the eyes are fixed at the 
extremity of a moveable feeler, adapting them to different 
focal distances, — or they can be drawn entirely within 
18 



206 ANATOMICAL CLASS BOOK. 

the head, for safe keeping, when not in use, precisely 
on the principle of care that we draw out the slides of 
an opera glass, and close them up again, when no longer 
needed. 



THE SOCKET IN WHICH THE EYE ROLLS. 

Several thin pieces of bone assist in the formation of the 
orbit, which, in a dry skull, is shaped much like a pear, 
with its large end turned outward. The upper plate of 
bone is arched, having the brain resting on it above, and 
the eye-ball moving under it below. Externally, the eyes 
are at considerable distance, but the inner termination of 
the orbits, answering to the small end of the fruit, are 
quite near together. At their points is a ragged hole, 
in each, through which the nerve of vision enters the 
brain. A large quantity of fat is deposited in these 
sockets, between the bones and eye-ball, that the latter 
may always move with perfect freedom, and without fric- 
tion, in all directions. After a long sickness, the cushion 
of fat is absorbed with that deposited in the bones, to sus- 
tain the system, ^hich accounts for the sinking in of the 
eye : as the person recovers, the stomach resumes the task 
of taking care of the body, the fat is deposited again, and 
the eye becomes prominent as before. 

GLOBE OF THE EYE. 

When detached from the surrounding parts, the eye- 
ball does not appear exactly round : it is, in outline, more 
than two thirds of a large sphere, with a portion of a lesser 
globe laid upon it. 

The use of this arrangement is obvious. If the ball 
had been actually round, the compass of vision would 
have been very limited : as it is, the smaller portion, by 
its short curve, protrudes so far beyond the socket, where 



ANATOMICAL CLASS-BOOK. 207 

the globe is lodged for safety, that the sphere of vision is 
very much enlarged. 

MUSCLES OF THE EYE. 

To move the ball, muscles -were necessary ; otherwise, 
animals would be obliged to turn their bodies as often as 
an object was to be seen. Of these, four are straight, 
going from the sides of the ball, to be fastened near the 
hole, at the termination of the bony cavity : their office 
is to hold the eye firmly, in a fixed position, as in steadily 
contemplating a painting. Two others are given, making 
six in the whole, to express, principally, the passions of 
the mind : they are denominated the oblique, in conse- 
quence of their oblique movement of the eye. One rolls 
it upward and inward, as in viewing a button, midway on 
the forehead ; the other, going through a loop, is so purely 
mechanical, that it has been the theme of admiration with 
philosophers in all ages, carries the eye downward and out- 
ward. The last action may be shown by looking at a but- 
ton, laid on the shoulder. Although these oblique muscles 
exist in monkeys and nearly all tribes of quadrupeds, they are 
imperfectly developed ; showing most conclusively that 
they were designed for expressing the feelings and passions 
of man — an ineffable language, which all the brute 
creation have the sagacity to understand. When one of 
the four straight muscles is shorter than its fellow on the 
opposite side, it produces the cross-eye or squinting. 



208 



ANATOMICAL CLASS BOOK. 
Fig. 80. 




Ex'planation oj Figure 80. 
This plan exhibits the muscles, viewed obliquely from the upper 
and outer side of the right eye. 
a. The eye-ball. 
&. Part of the upper eye-lid. 

c. Tunica Conjunctiva, or continuation of the common skin of the 
forehead, which turns over the edges of the lids, and is finally car- 
ried over the front of the globe, but perfectly transparent at this 
point. 

d. The integuments of the right side of the nose, 
e e. The optic nerve. 

y. The four straight muscles, with the levator or raising muscle 
of the upper eye-lid, together with the superior oblique muscle em- 
hracing the optic nerve where it enters the orbit. 

g. The levator of the lid drawn aside. 

h. Levator occuli, or superior straight muscle, — to roll the ball 
upward "^ 

i. Abductor occuli, rolls the ball outward. 

k. Adductor occuli, rolls it towards the nose. 

/. Depressor occuli, rolls the ball downward, towards the cheek. 

?H. The superior oblique muscle, passing through the loop at n, 

n. Called the trochlea, or pulley, but, in fact, a simple loop. 

o. Insertion of the superior oblique muscle in the eye-ball. 

p. The inferior oblique muscle, taking its rise from a bone. 

q. The insertion of the tendon of the inferior oblique muscle in 
the first coat of the ball. 




ANATOMICAL CLASS BOOK. 209 

COATS OF THE ETE. 

Such is the mechanical arrangement of the different 
coats or coverings of the eye, answering in use, to the 
brass tubes of a spy-glass, that one is fitted within the 
other, like a nest of boxes : they are three in number. 

Fig. 81. 

Explanation of Figure 81. 
This is a plan of the coals, or as 
they are sometimes termed, tunics. 

Reference should be made to this 
after reading the text. The natural 
figure of the eye, in outline, is pre- 
served. 

a. The Sclerotic, or first, hard 
tunic. 
'^a b. The Choroid, or fleecy tunic. 
c. The Retina, ov third and in- 
most tunic, which is an expansion of 
the optic nerve g — the certain seat 
of vision. 

d. The Cornea, or prominent, transparent circle, over which the 
lids close, in winking. 

e. The Crystaline lens, or little magnifying glass of the eye, 
about a quarter of an inch in diameter. 

/. Is the space filled by one of the fluids of the eye, and called 
the anterior chamber. 

g. The stump of the optic nerve, which is prolonged into the 
substance of the brain. 

1st. The first is the Sclerotic^ coat, thick, firm, and 
possessing but little sensibility. Its hardness gives secu- 
rity to the delicate membranes beyond ; affords attach- 
ment for the muscles; and by its elasticity, equally distends 
the ball J that none of the humors may suffer from pres- 
sure. Happily the hard coat is very rarely diseased. 
Fishes have a sclerotic coat strictly hard, being either 
cartilaginous or firm bone, graduated in this respect ac- 
cording to the depth to which they descend in search 
of food. Through this coat, in what is called the white 

^Sclerotic, from a Greek word meaning hard. 

18* 



210 ANATOMICAL CLASS BOOK. 

of the eye, the occulist plunges a needle to cure some 
kinds of blindness. 

2d. Choroid^ \s the name of the second coat, having 
a dark red color, and apparently slightly connected with 
the first. By carefully cutting off the sclerotic from a 
bullock's eye, with scissors, the choroid will be beautifully 
exhibited, sustaining the humors. Minute dissection, 
under a microscope, shows that this tunic is a complete 
web of arteries and veins ; — hence its reddish hue. Be- 
tween this and the sclerotic, fine silvery threads are seen, 
which hold a control over the Iris, yet to be described, — 
determining by their influence how much or how little 
light may safely be admitted into the eye. The inside of 
this membrane resembles closely woven wailed cloth, hav- 
ing a fleecy nap, similar to velvet, called Tapetum.i 
This tapetum is particularly interesting in a philosophical 
point of view, as on its shade of color, in a great measure, 
as will be more fully explained in the sequel, depends the 
power of seeing in the dark. 

3d. Retina,'^ so called from its resemblance to a net, 
completes the number, being the innermost and last. Its 
color is that of gum arabic, or ground glass : nothing can 
be more delicate, being too tender to bear its own weight. 
In^fact, it is the expansion of the optic nerve, the imme- 
diate seat of vision. To see it well, an eye should be 
taken to pieces in a tumbler of water. 

"^ ChoroideSf — like a lamb- skin, fleecy. 
iXapetum — resembling cloth, called tapestry. 
tRetiiia, — a net. 



ANATOMICAL CLASS BOOK 



211 




Explanation of Figure 82. 

from dissection of a human eye, the 
organ being represented of the pro- 
per size. 

a. The optic nerve. 

h b. The Sclerotic coat cut and 
turned outward. 

c. A circular portion of the Scle- 
rotica, being a rim of the white of 
the eye, cut, and turned upward, 
having in its embrace the cornea. 

d. Th.^ cornea, 
ee. One half the /?'fs,inits place, 

the other half being removed. 
f. The Pupil, soon to be descri- 
bed, with the crystalline lens in its place. 

g. The Ciliary circle, or second vertical partition, within the 
eye, behind the iris. 

h k. Choroid coat. 

i. The Ciliary j'^^'ocesses, or ruffle-like plaits of the ciliary circle, 
yet to be explained. A small portion of the iris is cut away to show 
them. 

k. A portion of the iris cut and turned back. 

I. The floating points of the ciliary processes, also turned back. 

m. The middle smooth part of the retina, seen by cutting a hole 
through the choroid coat. 

n. The roots of the ciliary processes, to which the black paint, 
secreted by the tapetum or inner surface of the choroides, adheres. 

o. The ciliary processes inserted into the sac which contains the 
cry st aline lens. 

THE CORXEA. 

Anteriorly, that clear, shining wall, resembling a watch 
crystal, which furnishes the membraneous box, is called 
the cornea. Simple as this thin crystal appears, it is 
infinitely curious in structure. It is made of thin pellu- 
cid plates, one over another, held together by a spongy 
elastic substance. By maceration in water a few hours, 
the sponge will absorb it to such a degree, that the plates 
may be distinctly felt to slide upon each other, between 
the thumb and finger. 

Little glands, like bags of oil, only to be seen by the 
most powerful microscope, are lodged under the first 
plate, which are continually oozing out their contents 



212 AI\ATOMICAL CLASS BOOK. 

upon the surface, which gives the sparkling brilliancy to 
this part of the eye. As death approaches, this fluid 
forms a pellicle, like a dark cloud, over the lower portion 
of the cornea. This formation is taken to be a sure indi- 
cation of approaching dissolution. See fig. 81, letter d, 
and fig. 82, letters c and d, for representation of the cornea. 

IRIS. 

By looking into a person's eye, there seems to be a ver- 
tical partition, either black, blue, or hazle, as the case 
may be, which prevents us from looking into the regions 
beyond, — having a round hole in its centre. This is the 
iris, while its central orifice is denominated the pupil. 
How the diameter of this hole is enlarged or diminished, 
has never been explained satisfactorily. One fact, how- 
ever, is certain, that the pupil is large or small, according 
to the quantity of light that may be necessary to the for- 
mation of a di^itinct picture of the object seen. — and this 
change is eflfectod without our being conscious of the 
action. 

From the reflection of^ such rays as are not admitted 
through the pupil, or central hole, we account for much 
of the lively brilliancy of the iris. On its back side it is 
rather fleecy. Over this is spread a black, blue, hazle, or 
tea-colored paint, which gives a permanent color to the 
eye. It has been remarked, that the eyes and hair ordi- 
narily correspond in color. Whenever the iris acts, as, for 
instance, it does in going from a dark into a light room, 
the pupil is made smaller, — acting uniformly in its fibres, 
to keep it circular. On returning to the dark apartment, 
the pupil enlarges again. A knowledge of this fact, will 
explain the reason of a painful sensation in the eye, caus- 
ed by a strong and sudden light. As soon as the iris has 
had time to diminish the size of its pupil, we can endure 



ANATOMICAL CLASS BOOK. 213 

the same luminous object with perfect comfort. When 
we leave a well-lighted room, on first going into a dark 
street, everything appears lurid and indistinct. The iris 
soon begins to enlarge the pupil, to admit more light, and 
when that has been accomplished, although in compara- 
tive darkness^ we recognise objects without an effort. 
Acting independently of the will, its duties are lik '■ those 
of a faithful sentinel, always consulting the safety of the 
splendid optical instrument confided to its care, v\ Ith re- 
ference to its subserviency to the being for whose use it 
was exclusively constructed. Were it otherwise, — were 
it left to our own care, how often it would be neglected, 
and indeed, totally ruined, solely for the want of undivided 
attention. 

Parrots have a voluntary control over the pupil, opening 
and closing it at pleasure. How this is done, or why, in 
the constitution of that bird, it is necessary, we cannot 
determine. Cats^ also, appear to have a similar power of 
graduating the quantity of light, admitted into their eyes, 
as it suits their own convenience. 

In carnivorous quadrupeds, the pupil is commonly oval 
and oblique, permitting them ir look from the bottom to 
the top of a tree without much elevation of the head. 
Gramnivorous quadrupeds have an oblong pupil, placed 
horizontally, with respect to the natural position of the 
body. This form gives them the faculty of surveying the 
expanse of a field, at once. See fig. 82, letters e e, and k> 
Fig. 83, letters c c, 

CILIARY PROCESSES. 

Directly behind the iris, is a second curtain, having a 
central hole through it, corresponding with that through 
the first curtain, but nearly as large as the whole diameter 
of the lens. All the luminous rays which are converged 
by the convexity of the cornea, which is, in effect, a piano 



214 ANATOMICAL CLASS BOOK. 

convex lense, cannot enter through the pupil ; many of 
them strike the plane of the iris, and are reflected back, 
as on a looking-glass, without penetrating its substance. 
If any rays were to get through, by such an irregular pro- 
cess, it would produce great confusion, by destroying the 
outline and vividness of the image previously made on the 
retina, through the natural opening. To prevent such 
mishaps, the paint on the back of the iris is to absorb such 
rays as are not reflected, and have a tendency therefore to 
pass onward. Nature, as though fearful that circumstan- 
ces might so alter the condition of the pigment,^ as that 
some light, notwithstanding this precaution, might pene- 
trate, has interposed this second veil, — solely it is sup- 
posed to stop all wandering rays. 

This ciliary curtain presents three thicknesses, and 
lastly, has a thick coat of black paint on its back. In or- 
der to give it treble security, as it regards thickness, it is 
plaited like the folds of a ruffle. There are seventy folds 
in the human eye, of equal width, nicely laid, one over 
the other. A part so highly important, cannot be over 
Ipoked in studying the philosophy of vision. 

•^ 

^ Pigment, — paint, 



ANATOMICAL CLASS BOOK. 
Fiff. 83. 



215 




Explanation of Fig. 83. 

This plan presents a longitudinal section of the left eye and orbit. 

a. The upper eye-lid, shut. 

6. The cornea. 

cc. The cut edges of the iris. 

d. The piijjil or round hole through the centre of the iris. 
which, in the Uving eye, resembles a black, highly polished dot. 

ee. The cut edges of the sclerotic and choroid tunics, with the 
retina, before exhibited in the preceding drawings. 

/. The crystaline lens, as it is lodged, with reference to other 
parts. 

gg. The Ciliary processes continued from the choroid coat. The 
plaits are here distinctly seen. 

h. The optic nerve running from the brain, through the bones, 
to the globe of the eye, apparently closely embraced by the straight 
muscles. 

i. The levator muscle that raises the upper eye-lid. 

k. The upper straight muscle of the eye. 

/. Inferior straight muscle, its antagonist, on the under side of 
the ball, called depressor occidi. 

m. A section of the inferior oblique muscle, used in rolling the 
eye upward and inward, as in looking at a button laid above the root 
of the nose. The superior oblique, passing through a loop, carries 
the eye downward and outward, as in looking at the top of the 
shoulder. These two muscles, by old writers, were termed rotato- 
res and amatores, in allusion to their office of rolling the ball in ex- 
pressing passions. 

nn, A section of the blood vessels and nerves, with a large 
quantity of fat, surrounding the optic nerve. 



216 ANATOMICAL CLASS BOOK. 

HUMORS OF THE EYE. 

By humors, writers mean the fluids which distend the 
eye-ball. They are three in number, — possessing differ- 
ent densities, and varying much in quality, quantity and 
use. Besides fulfilling the first intention, — viz, disten- 
sion, — they are so purely transparent, as to offer no ob- 
struction to the free passage of light. Those only inter- 
ested in this description, as general scholars, by close ex- 
amination will have a perfect idea of them, and will con- 
sequently understand the real nature of some of the many 
causes that weaken the power of vision, or ultimately pro- 
duce a total blindness. The gratification afforded by the 
examination of a bullock's eye, — tracing the several parts 
by this paper, will be an ample compensation for the labor, 
because it will forever fix on the mind interesting facts, 
and lead the reader, insensibly, to a course of reflections, 
productive of much intellectual enjoyment. 

AQUEOUS HUMOR.=^ 

The aqueous humor is the first in the order of demon- 
stration, lying directly back of the cornea, — so clear, 
that one unacquainted with the existence of it, would not 
suspect a fluid there. In volume, it is far less than the 
others : it keeps the cornea prominent, always at the same 
distance from the iris, in the early periods of life. The 
space occupied by the aqueous humor, is called the ante- 
rior chamber of the eye. (See fig. 81, letter/!) Passing 
freely through the pupil, it also fills an exceedingly thin 
apartment, the circumference of the iris, called the pos- 
terior chamber. Thus it will be comprehended that the 
iris, or in familiar language, first curtain, is actually sus- 
pended and floating in a liquor. 

* Aqueous like water. 



ANATOMICAL CLASS BOOK. 217 

Were it not for such a contrivance, the iris would soon 
become dry and shrivelled, by the intensity of the sun, 
and therefore rendered totally unfit to perform its appro- 
priate office of opening and closing the pupil. The aque- 
ous humor is never suffered to remain long at a time, but, 
on the contrary, is constantly poured in and again drawn 
off by an infinite number of invisible ducts. By being 
stationary, it would become speedily turbid, and finally 
lose its transparency. A knowledge of the rapidity of the 
secretion has been the means of encouraging occulists to 
undertake novel methods of extracting cataracts, a kind 
of dark mote, through the cornea, as the most certain mode 
of restoring sight. Twenty-four hours after drawing off 
the aqueous humor, by a puncture, the "anterior chamber 
will be full again. 

Old age, characterized by a gradual decay in the vigor 
of all the individual organs, shows also its insidious ap- 
proach in the eye. Vessels that have toiled with untiring 
diligence to the meridian of life, begin to show a loss 
of energy. Those which have carried the new, pure 
liquid, forward a less quantity in a given time than for- 
merly, — while those whose task it was to convey away 
the old stock, are dilatory in the performance of their 
work. Hence, from, being kept too long in the reservoir, 
in consequence of a tendency to become more turbid, it 
does not allow the light to pass with its former facility to the 
nerve ; elderly persons, therefore, have indistinct vision 
from this cause, similar to looking through a smoky at- 
mosphere. Fishes have no aqueous humor at all, as it 
could be of no service in the element in which they swim 

Kept, as the humor is, in its own capsule, it gives other 
advantages to the apparatus of vision : it is a concavo-con- 
vex glass, absolutely and indispensably requisite in an in- 
strument that will produce an image by the same laws 
that govern the eye. A sensible diminution in the quantity 
19 



218 ANATOMICAL CLASS BOOK. 

of this fluid, is very apparent in people advanced in years : 
the cornea becomes flatter ; the segment of it is so 
altered, that rays of light are no longer converged as in 
younger days. This, together with corresponding de- 
rangements within the globe, constitutes the long-sighted- 
ness of old age, — mechanically overcome by wearing 
convex spectacles. So gradually are the changes wrought 
by age, that glasses of different focal distances are sought 
from time to time, to keep pace with the progress of 
decay. 

The ingenuity of man is nowhere more curiously dis- 
played, than in thus availing himself of his discovery of 
the laws of refraction, in producing artificial lenses to 
gratify his eye, a never failing source of enjoyment, long 
after nature has begun to draw the blind that will ulti- 
mately close between him and the world forever. 



As magnifying glasses of different refractive powers 
give perfection to optical apparatus, so it is with respect 
to the lenses within the ball. By crystaline lens, is simply 
meant a body like a button, resembling pure flint glass, 
somewhat of the shape of a common sun glass, convex on 
both sides. Its posterior convexity is greater than its 
anterior, — thereby bringing the rays to a point a little dis- 
tance behind it. Careful investigation shows that this 
lens is made of a series of plates, applied to each other 
like the coats of an onion : the centre is firmer than the 
edges. 

As a whole, it possesses a highly refractive property, but 
in different degrees, according to the thickness of the 
lens, — receding from the centre to the circumference. 
Over the whole, to keep it from sliding in any direction, 

* Crystaline lenSj — resembling^ crystal or glass. 



ANATOMICAL CLASS BOOK. 219 

that the centre may not get without the axis of vision, 
is an envelope, having connexion with all the coats, where 
they are united on the borders of the cornea, and where 
it joins the white part of the eye. Being equally trans- 
parent with the lens itself, it cannot be conveniently ex- 
hibited. 

Cataracts, the most frequent cause of blindness, origi- 
nate in the lens: sometimes half way between the centre 
and margin, but ordinarily in the centre. They are either 
a peculiar deposition of opaque or nulky matter, entirely 
preventing the ingress of light, or there is an opacity of 
^^ome of the internal layers of plates, equally destructive to 
vision. Many children are born with this affection ; and 
at all ages, they are liable to form. To remove cataracts 
by extraction, the operator slides a sharp, thin knife, re- 
sembling a lancet, through the cornea, from one side to 
the other, cutting one half from its natural attachment — 
leaving it in the form of a flap, thus : 

Fig. 84. 




Explanation of Fig. 84. 
This plan represents an eye, surrounded by its natural appen- 
dages, with a knife passing through the anterior chamber. A dotted 
line indicates the lower edge of the flap, made by cutting off just one 
half the cornea from its attachment with the sclerotica, in order to al- 
low the crystaline lens to escape, whenever the knife is withdrawn. 

As a matter of course, the aqueous humor escapes in a 
twinkling, at the same moment, the capsule of the lens, 
previously ruptured, designedly, by the point of the knife, 



320 ANATOMICAL CLASS BOOK. 

as it slides along, acts upon the lens by spontaneous con- 
traction, and protrudes it through the wound. Undoubt- 
edly the grasp which the straight muscles have on the ball, 
accelerates its escape. 

Thus, in taking away the obstruction to sight, the whole 
lens is extracted. 

To couch, an operation often mentioned, and often per- 
formed, is to thrust a delicate needle through the white 
of the eye, just on its border, till the point reaches the 
lens, which is then depressed into the lower part of the 
eye, below the optic axis, so that light may, by entering 
the pupil, arrive at the nerve. In this last operation, fears 
are always entertained, that the lens may rise again to its 
former position, rendering a repetition of the operation 
indispensable. Secondary cataracts sometimes form, after 
couching or extraction, and arise in consequence of a thick- 
ening and opacity of the capsule^ which is left behind. 
Such cases are more alarming in their progress than a 
disease of the lens, as no surgeon is warranted in promis- 
ing even a partial relief. If he attempted to tear away 
the membrane, he might also rend every other within the 
globe. 

A ^ew facts of this kind which have a practical bearing, 
more or less interesting to every person, may lead to cor- 
rect views in relation to some of the diseases which are 
common to this curious organ. 



AxVATOMICAL CLASS BOOK. 



221 



.85. 




Explanation of Figure 85. 
This is a scheme showing how 
a bad o|)erator, by introducing the 
couching needle too near the cor- 
nea, may rupture the ciliaiy pro- 
cesses, and actually divide the 
lens in two pieces without moving 
it from the optic axis. 

A. The vitreous humor. 

B. The lens. 

CC Ciliary processes, torn by 
the lower part of the needle, 
thereby doing great violence and 
a permanent injury to the organ. 

DD. The iris. 



E. The anterior chamber of the aqueous humor. 




Explanation of Fig. 86. 
' This figure represents 
the mode, and, in fact, 
the pli3ce into which the 
couching needle is intro- 
duced, in the operation 
of couching. 

A. The pupil is seen 
through the transparent 
cornea. 

B. The ins. 



-^ 15. ine ins. 

C. The needle, wiih the handle elevated so as to depress the 



point. 

D. The lens and point of the needle in outline; this precisely 
represents the position of the lens after couching. 

VITREOUS HUMOR. 

Beyond the two humors we have been describing, is 
the third, differing essentially from either of them. In 
volume it far exceeds the others, — occupying more than 
two thirds of the whole interior of the ball. Its consist- 
ence is that of the white of an egg, but kept in place by 
its own capsule. When the sac is punctured with a pin, 
it flows out slowly in consequence of its adhesiveness. 
Like the preceding humors, it is transparent, allowing the 
free passage of light through its substance, and also pos« 
19* 



2^2 



ANATOMICAL CLASS BOOK. 



sesses the additional quality of allowing the rays to sepa- 
rate again, as they leave the point at which they were 
converged just back of the lens. Observation proves 
that the \ itreous humor is kept in place by being lodged 
in cells. Perhaps a piece of sponge might give a tolerable 
idea of the cellular structure, admitting it to be as trans- 
parent as the water which it absorbs. On its fore part it 
has a depression, in which the posterior convexity of the 
lens is lodged, — as represented in this diagram. Concave, 
therefore, in front, and convex behind, gives another kind 
of optical glass, known as the meniscus ^ — the crescent, 
faintly resembling the first quarter of the new moon. 

Fig. 87. 



Explanation of Figure 87. 
One dotted line indicates, in this 
diagram, the aqueous hutnor; an- 
other the ii is, and n third the lens, 
and the foui'th the vitreous humor. 
Let it be remembered that all the 
space between the back side of the 
lens and optic nerve, is filled com- 
pletely, with the glairy, vitreous 
humor, the third fluid, and inmost 
.of the eye. 



OPTIC NERVE. 

Any person possessing an ordinary share of curiosity, 
can examine the optic nerve, at leisure, in slaughter 
houses, fish markets, and in fowls. In the human eye, — 
or rather extending from the globe to the brain, — the 
optic nerve is very much like a cotton cord, somewhat 
larger than a wheat straw, of a mealy whiteness, and not 
far from three quarters of an inch in length. Arising from 
the substance of the brain, it traverses the bony canal till 
it reaches the back of the eye-ball ; as soon as it arrives 
in contact, as it were, it is suddenly divided into innumer- 
able filaments, which wend their way into the globe, 




ANATOMICAL CLASS BOOK. 223 

through very minute holes. From a fanciful resemblance 
to a sieve, this spot on the sclerotica, is called the cribriform 
plate. When the threads have emerged within, they as- 
sume another form, by expanding into a web, constituting 
the third or inmost box. Some believe the nerve is spread 
on a thin, unseen membrane, in the form of a highly or- 
ganized nervous paste. Here, on this pulp, having con- 
siderable range of surface, is the sole seat of vision. A 
vulgar opinion presupposes some exceedingly acute nervous 
point, — the exquisite place of vision. Nothing, however, 
is more absurd ; vision includes considerable surface. In 
the centre of the substance of the nerve, an artery pene- 
trates the eye, accompanying the JilameJits, to nourish the 
humors. When the cornea has been cut away, and the 
iris detached, this vessel may be distinguished, of a bright 
scarlet, spreading its hair-like branches about, like the 
limbs of a tree. The nerves which give sensation to the 
eye, connecting it with the system, may be noticed, as 
previously remarked, lying between the two first coats. 
The optic nerve conveys to the mind the sensation of the 
existence of things, as perceived by the eye, while the 
commands of the same mind are conveyed to the organ 
by these little threads of nerves, so insignificant, as to be 
often overlooked in a dissection made purposely for them. 



224 



ANATOxMICAL CLASS BOOK. 




Explanation of Fig. 88. 
In this figure, the cornea is cut away, and the sclerotic dissected 
back. This is a beautiful and easil}^ accomplished dissection. In a 
bullock's eye all these delicate nerves can be readily displayed. A 
pair of sharp pointed scissors and a few pins, to hold parts to a board, 
are the proper instruments. In schools, ladies could display the 
whole of this beautiful optical apparatus, 

a. The optic nerve. 

b. The sclerotic coat turned back, so as to show the vessels of 
the choroid coat. 

cc. The ciliary nerves, seen piercing the sclerotic coat, ^nd p^LSs- 
ing forward to be distributed to the iris. The iris, so highly 
organized, is not supplied by any nervous influence from the optic, 
but by the hair-like nerves, here displayed, creeping to its margiri 
between the two exterior coais. 

d. A small nerve passing from the same source to the same ter- 
mination, but giving off no visible branches. 

ee. Two vencE vorticoscB, or whirling veins, so denominated, be- 
cause they seem to fall into shapes, resembling falling jets of water; 
these return the blood from the eye, sent in by its central and other 
arteries. 

/. A point of the sclerotic, through which the trunk of one of the 
veins has passed. 

g. A lesser vein. 

II. The circular point of union, where all the coats of the eye, 
together with the cornea and iris, seem to be glued firmly together! 

I. The iris. 



ANATOMICAL CLASS BOOK, 225 

h. The straight fibres of the iris. 

I. A circle of fibres or vessels, which divide the iris into the 
larger circle k — and the lesser one in. • 

771. This letter points to the lesser circle of the iris, 
n. The fibies of the lesser circle. 
0. The pupil. 



Lastly, to complete the internal structure, and fit it for 
the performance of its destined office, the inside surface 
of the second coat, cJioroides, is thoroughly painted black. 
In the order of explanation, this paint is just behind the 
retina. When the humors have been taken out, the pig- 
ment is readily examined. The use of it is very obvious ; 
viz., to absorb any aberrating or unnecessary rays of light, 
which would confuse the vision, or destroy the intensity 
of the impression on the expanded retina, or to suffocate 
them entirely. 

SKIN OF THE EYE, OR TUNICA CONJUNCTIVA. 

Behind, the eye, by its long cord of- optic nerve, seems 
to rest on one extremity of an axle : — in front, the skin, 
passing over the eye, as it comes down from the forehead, 
to join the cheek, is the other. 

To comprehend, clearly, the manner in which the eye 
is fastened, before, — observe how the skin turns over the 
edge of the lid, going about three quarters of an inch back, 
striking the ball to which it is made fast, then folded back 
upon itself, adhering to the whole anterior surface of the 
cornea, — dipping down and finally mounting over the 
margin of the lower lid, and ultimately loosing itself on 
the face. As we cannot recognise this on a living eye, 
it will at once lead one to suppose it is as clear as glass, 
which is the case. Streaks of blood, when the eye is in- 

* Pigmentum Nigrum ™ black paint. 



226 ANATOMICAL CLASS BOOK. 

flamed, lie covered over by the tunica conjunctiva. Now 
if particles o/ sand, or other irritating substances get under 
either eye-lid, they cannot possibly enter but little way, 
before reaching the duplication of this transparent skin ; 
there is no danger, therefore ; the offending matter cannot 
get so far between the socket and ball, backward, as to 
abridge the free motion of the organ, or do a permanent 
injury to the parts. This partition, or doubling over of 
the conjunctiva, is a curious provision, as we are thereby 
enabled to reach the source of irritation. 

The principle of introducing eye-stones, to extract 
foreign matter, is this, and not owing as vulgarly sup- 
posed, to the crawling about of a smooth piece of sulphate 
of lime, on some forty or fifty feet. The stone is so much 
larger than the extraneous body, already there, that it ex- 
cites a proportionably larger quantity of tears, to wash it 
away : in effect, therefore, we submit to a greater tempo- 
rary evil, to get rid of a lesser one. 

Serpents annually shed their skins, which, unaccount- 
able as it at first appears, are whole over the eyes. That 
thin sheet, so very clear and fine in texture, is the con- 
junctiva, showing its origin, — hence a similar origin 
may safely be inferred over other eyes. Every species of 
animal with which naturalists are conversant, possess this 
defensive transparent membrane. 

THIRD EYE-LID, OR MEMBRANA NICTITANS. 

A third eye-lid is given such animals as are destitute 
of hands, or are incapacitated, by the arrangement of their 
limbs, from reaching their eyes. This is called mem- 
brana nictitans, — and a more striking piece of mechan- 
ism there is not in existence. It slides from one angle 
of the eye to the opposite one, under the first pair of lids, 
— and that, too, whether the others are open or shut. 



ANATOMICAL CLASS BOOK. 227 

being totally independent of them in muscular action. 
Its use cannot be mistaken : it is on purpose for clearing 
away matter that may be irritating to the eye. Any ex- 
traneous substance is brushed from the cornea in an 
instant, by the broad sweep of the night lid. Birds that 
seek their food in the night, as owls, defend their irrita- 
ble organs, through the glare of daylight, by drawing over 
this singular curtain. Dogs, cats, foxes, wolves, bears, 
lions, tigers, &c, can each of them, by this brush, re- 
move the minutest mote from the cornea, more expedi- 
tiously than any occulist on the globe. 

TEARS. 

Perfection is everywhere observed in animal mechan- 
ics. The eye would soon become a useless instrument 
notwithstanding the nice adjustment of its several parts, 
were it not for the external apparatus of eye-lids, glands 
and tears, whose combined action keeps it always in a 
condition to be useful. Were not the cornea frequently 
moistened, it would become dry and shrivelled. To ob- 
viate this, a sack of fluid is fixed just under the edge of 
the orbit, above the eye-ball, which is continually pouring 
out its contents by the pressure and rolling of the eye. 
Flowing through numberless apertures, it washes the 
crystal and finally passing into grooves, on the inner 
marc^in of both eye-lids, runs to their terminations in a 
small pin-like orifice, at the inner angle. To keep them 
open^ a hoop is set in the mouth of this tear tube. This, 
too, can be shown by turning the lid outward by the 
finger. Finally, the tears are conveyed into the nose 
through a bony tube, answering the double purpose of 
keeping moist the lining membrane, on which the sense 
of smell depends. On both eye-lids, at the roots of the 
eye-lashes, are in each, a row of glands, equivalent to 



228 



ANATOMICAL CLASS BOOK. 



bags, smaller than pin heads, which ooze out an oily 
secretion, to prevent the adhesion of them together, as is 
sometimes the case when the eyes are much inflamed. 
Surely such manifest provision for contingencies, is another 
beautiful illustration of super-human contrivance. 

Fig. 89. 

Explanation of Fig. 89, 

This plan exhibits the natural 

size of the passages of the tears. 

a Is the lachrymal gland, or 

organ that secretes the tears; 

showing lis natural situation, 

with i-espect to the eye-lids. 

bb. The eyelids v/idely opened, 

c. The situation of the punc- 

■ ta lachrymalia,ov the holes at 

the inner angles of the lids, 

through whicli the tears flow, 

to get into the tube which 

finally conveys the fluid to the 

nose. 

dd. The ducts continued from 
the punct a lachrymalia. 

ee. The angles which the 
ducts form after leaving the 
puncta. 

/. The termination of the lachrymal ducts in gg. 
gg. The lachi-ymal sac. 
h. The nasal duct, continued from the lachrym.al sac. 




WHY DO AGED PERSONS REQUIRE CONVEX GLASSES? 

Age gradually relaxes the tension of the whole system ; 
the eye, therefore, suffers in a corresponding ratio. The 
cornea becomes less prominent: — the convexity of the 
lens is also diminished, and the rays of light are conse- 
quently less convergent than formerly. The picture of 
the object is faint, because the rays have a tendency, by 
their divergency, to impinge at a supposable plane, be- 
yond the retina. 



ANATOMICAL CLASS BOOK. 
Fig. 90. 



229 




Explanation of Fig. 90. 
In this figure is represented the effect of old age on the humors ; 
without the intervention of the glass A, the raj^s have a direction 
which would form the image at some distance beyond the retina, as 
at B. But, by the convex glass A, which, for example, is the spec- 
tacle worn by aged people, the direction of the ra^-s of li2,ht is so 
corrected, that the image falls accurately on the bottom of the eye, 
or retina. 

When the convex lens is interposed between the eye 
and object, as represented in the above diagram, the rays 
are made more converging, — so that the picture strikes 
exactly and distinctly on the nerve. People slide their 
spectacles on the nose unconsciously till the true focus is 
procured. 

WHY DO NEAR-SIGHTED PERSONS SEE INDISTINCTLY? 

Either the crystaline lens, but more generally the cor- 
nea, is too prominent — converging the light too sudden- 
ly ; — that is, converging the luminous rays at an unnatural 
place within the vitreous humor. An indistinct outline of 
the object is the effect of their great divergency, after 
decussating — before they arrive at the retina. The fol- 
lowing diagrams will illustrate the subject far better than 
a whole volume of written explanations. 

Fig.&l. 




230 



ANATOMICAL CLASS BOOK. 



Explanations of Fig. 91. 
In this figure, the convexity of the cornea, or the focal powers 
of the lens, being too great for the length of the axis of the eye, the 
image is formed at A, before the rays reach the surface of the retina, 
or inner box, illustrated in Fig. 81, letter c; and after coming accu- 
rately to the point, they again begin to diverge ; which diverging 
rays, striking the surface of the retina, give the indistinct vision of 
the near-sighted individual. But as this indistinctness of vision 
proceeds from no opacity, but only the disproportion of the convexity 
of the eye to the diameter, the defect is corrected by a concave glass, 
represented in the next figure. 

Concave glasses are the restoratives of the near-sighted 
eye, by separating the rays, and carrying the image so 
far back as to place it on the retina. Old age, the de- 
struction of the first eye, eventually restores the near- 
sighted, by the gradual flattening of the cornea, till at 
threescore and ten such persons can see clearly and 
distinctly without artificial aid. Many near-sighted people 
totally ruin the organ by prematurely wearing glasses, as 
a focus is established which neither glasses can keep 
pace with in age, nor age thoroughly overcome. 

Fig. 93. 




Explanations of Fig. 92. 
The effect of this glass being exactly the reverse of the convex, 
it causes the rays to fall upon the surface of the eye, so far diverg- 
ing from the perpendicular line, as to correct the too great converg- 
ence, caused by the convexity of the humors. When a near-sighted 
person has brought the object near enouo^h to the eye to see it dis- 
tinctly, he sees more minutely and consequently more clearly, 
because he sees the object larger, and as a person with a common 
eye does, when assisted with a magnifying glass. A near-sighted 
person sees distant objects indistinctly, and, as the eye, in conse- 
quence, rests with less accuracy upon surrounding objects, the 
piercing look of the eye is very much diminished; and it has, more- 
over, a dulness and heaviness of aspect. Again, the near-sighted 
person knits his eye-brows, and half closes the eye-lids; this he 
does unconsciously, to change the direction of the rays, and to cor- 



ANATOMICAL CLASS BOOK. 231 

rect the inaccuracy of the image. Near-sighted people have but 
little expies-ion ; the countenance loses all its dignity, by habitually 
wearing glasses. 

THE IMAGE OF AN OBJECT IN THE EYE, IS INVERTED. 

Rays of light going from the upper and lower points of 
an object, are refracted towards the perpendicular ; that is, 
bent out of the course which they have a tendency to 
run, by the crystaline lens behind, where they unite iii 
a point, — and, then crossing, diverge again. Here then, 
the image is bottom upward, as will be noticed in the 
preceding diagrams by the arrow, and its image on the 
retina. Decussation is indispensable to the vision of 
things. An object could not be represented on a point ; 
there must be surface to create an image on, and by the 
laws of optics, the representation of the object, without an 
additional glass within the eye, must necessarily be as it 
is — bottom upward. 

THE OBJECT APPEARS IN ITS TRUE POSITION, 

Habit is supposed to be the cause of seeing objects as 
they really exist in relation to surrounding bodies. An 
attempt has been made to prove that the cornea is the true 
seat of vision, and that we see by means of erect and re- 
flected, and not by refracted and inverted images. A {q\\ 
philosophers conceive that the mind contemplates the ob- 
ject only, without reference to its representative on the 
retina, which is made there as a natural result. Certain 
it is, that without the image, there is no vision. 

How the brain is operated upon by the light that de- 
fines the object, will probably never be known. The 
minuteness of the picture traced on the retina, precisely 
like the object in every minute particular, is truly aston- 
ishing. By cutting off the coats of a bullock's eye and 



232 ANATOMICAL CLASS BOOK. 

holding a clean white paper near, this beautiful exhibition 
can be leisurely observed. If a sheet of white cotton cloth, 
six feet square, is elevated 24,000 feet in the air, the eye 
being supposed one inch in diameter, the miniature of the 
cloth on the retina will be only one eight thousandth part 
of an inch square ; which is equivalent to the 666th part 
of a line, — being only the 66th part of the width of a 
common hair ! 

WJTH BOTH EYES ONLY ONE OBJECT IS SEEN. 

At one side of the centre of each eye, there is a surface 
more susceptible of visual impressions than any other. 
These points correspond in both eyes — being precisely 
on the two retinas alike. An impression therefore on one, 
provided the light strikes them equally, produces precisely 
the same effect on both. This, instead of making vexa- 
tion, gives strength and greater vividness, as the images 
are on surfaces of the same structure, transmitting, through 
the two optic nerves, the same idea, or that indescribable 
something that creates an idea. The optic axes, by this 
explanation, will be understood. If one eye is distorted, 
— pressed by the finger one side, when we are in the act 
of contemplating an object, it will appear double, but less 
distinct in the one so distorted. The rationale is this J 
viz. the visual surface on which the image is made, so 
exactly alike in both eyes, as to call up but one idea, being 
forced out of the optic axis, the rays still make the pic- 
ture, but on a surface, less highly organized, — that does 
not correspond with the surface on that retina which has 
not been disturbed. The two images have now different 
localities. No course of experiments are more within the 
reach of the scholar. 



ANATOMICAL CLASS BOOK. 



233 




Fig. 94. 




A^ 



the same relation to the retinas in both eyes 



Explanation of Fig. 93. 
In this fio;nre, B, B. the eyes; 
having their axes directed to A, 
will see the object C, double, some- 
where near the outline D, D. Be- 
cause the line of the direction of 
the rays from C, do not strike the 
retina in the same relation to the 
axis A, B, in both eyes. If a can- 
dle is placed at the distance of ten 
feet, and I hold my finger at arm's 
length, between the eye and the 
candle, when I look at the candle, 
my linger appears double, and 
when I look at the finger, the can- 
dle is double. 



Explanation oj Fig. 94. 
A is exactly in the centre of the 
axes of both eyes ; consequently it 
is distinctly seen, and it also ap- 
pears single, because the fov m of it 
strikes upon ihe points of the retina, 
opposite to the pupils in both eyes. 
Those points have a correspond- 
ence, and the object is strengthened 
in the liveliness of the image. 
Again, the object B will be seen 
fainter, but single and correct. It 
will appear so because there is only 
one spot in each eye, which pos- 
sesses the degree of sensibility ne- 
cessary to perfect vi-ion; thus, it 
will be understood, the object will 
appear single, as the rays of light 
proceeding from it have exactly 



CROSS-EYED PERSONS SEE ONLY WITH ONE EYE. 

With such as have a permanent squint, (cross-eye,) only 
one eye is attended to, though they may not be apprehen- 
sive of the fact. From continued neglect, the distorted 
organ wanders farther and farther from the axis of vision, 
20* 



234 ANATOMICAL CLASS BOOK. 

till it finally becomes totally useless : hence one is doubt- 
ful, at times^ which way the cross-eyed person is looking, 
from a want of parallelism in the motions of the eyes. 
When the wandering eye is exclusively attended to, the 
vision appears unimpaired. The image is well painted in 
the natural one, but weak in the other, solely because the 
place of the image does not correspond with the place of 
the image in the first. The mind, instinctively, therefore, 
is devoted to the eye that gives the liveliest impression, to 
the entire neglect of its aberrating fellow. 

THE PUPILS OF AN ALBENO's EYES ARE RED. 

If a person is born without the pigmentum nigrum, — 
which is the paint to suffocate all unnecessary light, after 
the image is formed,- — the blood vessels of which the 
tunica choroides or second coat is made, are not hidden ; 
consequently, they show through the transparent humors, 
like a sparkling red gem, the size of the diameter of the 
pupil. Such persons can see better in a weak light than 
in broad day, because the brightness of the sun's light 
dazzles, and produces a tremulous motion in the whole or- 
gan. As an evidence that this redness is caused by the 
blood in the vessels, after death, when it coagulates, the 
redness in a great measure disappears. White rabbits, 
white mice, besides a vast variety of birds, have no pig- 
ment on the choroides^ and are therefore distinguished for 
red pupils. The existence of the pigmentum nigrum, is 
an evidence of a day-seeing eye. In man the want of it, 
constituting the albino, is an anomaly. 

A morbid action of the absorbents sometimes removes 
the paint, and the pupil, to the surprise of observers, be- 
comes scarlet. A partial absorption of it is often the 
cause of a diminution of the original powers of vision . 
under such circumstances, the pupil assumes a bronze 



ANATOMICAL CLASS BOOK. 235 

hue, accompanied by a debility and tremor of the globe 
under the influence of a moderate degree of light. 

MANY ANIMALS SEE IN THE DARK. 

Owls, fishes, cats, bats, &c, instead of the piginentum 
nigrum, have a silvery paint of a metallic lustre, where 
others have the black paint, which operates like a concave 
mirror, in reflecting the light from point to point, within 
the eye, illuminating it, till its concentration excites the 
retina to perceive. When viewing a cat's eyes in the re- 
mote part of a dark room, there are certain positions, in 
which they are seen by the observer, by the reflected light 
within themselves, as though they were phosphorescent : 
their brilliancy is very peculiar. Upon the principle of a 
looking-glass behind the retina, all the night prowling an- 
imals are qualified for seeing with those few rays of light, 
which the constitution of their eyes is formed for collect- 
ing in the dark. By daylight, they perceive objects, as 
man does in the dark, indistinctly. 

Nature is remarkably economical in the use of matter 
which enters into the composition of animal bodies, if a 
man be kept a long time in a perfectly dark room, the 
black pigment is taken away ; but a compensation is giv- 
en him, for he can then see as perfectly in the dark, as he 
could before in the light. On the other hand, the paint 
is deposited again when he is restored to the light of day. 
This point has been decided in the persons of state pris- 
oners kept in the dungeons of European despots. 

FISHES CANNOT SEE IN AIR AS WELL AS IN WATER. 

When the rays of light pass from a rarer to a denser 
medium, as from air into the aqueous humor of the eye, 
they are refracted towards the perpendicular. Now the 
fish has but a drop as it were, of aqueous humor, and^ 



236 ANATOMICAL CLASS BOOK. 

moreover, the light arrives at its eyes through the whole 
body of water above. The light is refracted only in a 
small degree in entering its eye, because the humor is of 
the same density of the fluid through which the light is 
transmitted. The cornea is quite flat ; if it were promi- 
nent, like the human eye, the sphere of vision would be 
too circumscribed ; — but by giving a prominence to the 
whole, and placing the crystaline lens in the fore part 
of the eye, they have a long diameter, — and with the 
provision of a large pupil, are completely fitted for seeing 
in the element in which they were destined to live. With 
an eye of this description they must necessarily see in air, 
as other animals see in water. 

Those animals whose eyes are organized for seeing in 
water, see but indifferently in air. Hence, in those cases 
where the habits of the animal require it to see in both 
elements it is provided with two sets of eyes, or with eyes 
accommodated for seeing in both. 

It cannot be denied, that, in general, land animals can 
see underwater, and aquatic animals in air; even man 
sees under water, although the contrary has been main- 
tained. It is not, however, possible that the same eye is 
ever so organized as to see equally well in both elements. 
Land animals always sec indifferently in water, and 
aquatic animals imperfectly in air. The one is long- 
sighted in water, and the other short-sighted in air. An 
animal in which the eye is adapted for seeing equally well 
in air and water, can have but imperfect vision in either. 
These conclusions are in conformity with w^hat is known 
of the power of vision in those animals which live partly 
on the land and partly in the water. The seal lives in 
both elements ; but it has but imperfect vision in the air. 

We have the most satisfactory evidence of the short- 
sightedness of seals, from a series of experiments and ob- 
servations, made in Boston harbor. 



ANATOMICAL CLASS BOOK. 237 

As a light looses more of its power in passing through 
water, than in passing through air, and is still more weak- 
ened in its progress through the membranes, it follows, 
that owing to this cause, vision must be less distinct un- 
der water than in the air. 

MAN CANNOT SEE DISTINCTLY UNDER WATER. 

A man under water, sees objects as a very aged per- 
son sees through a concave glass, placed close to the eye. 
The fish is long-sighted under water, and man is short- 
sighted. If he uses spectacles, whose convexity is just 
equal on both sides to the cornea of his own eye, he will 
see under water distinctly. The necessity of this is ob- 
vious ; the aqueous humor is of the same density with the 
water, and there cannot, therefore, be any refraction of 
the rays in passing from the water into the land-seeing 
eye. 

Euclid supposed that vision was occasioned by the 
emission of rays from the eye to the object. He thought 
it more natural to suppose that an animate substance gave 
an emanation, than that an inanimate one did. In 1560, 
the opinion that the rays entered the eye, was established. 
Kepler, in 1600, showed, geometrically, how the rays 
were refracted through all the humors, so as to form a dis- 
stinct picture on the retina ; and he also demonstrated 
the effect of glasses on the eyes. 

HOW^ DOES THE EYE ADAPT ITSELF TO THE DISTANCE OF 
OBJECTS. 

No one has satisfactorily answered this question. One 
philosopher supposes the eye at rest, when we examine a 
distant object, as a mountain, the spire of a church, or a 
landscape, but, that in the act of seeing near objects, 
there is an effort. It has been supposed that this effort 



238 ANATOMICAL CLASS BOOK. 

is the action of the straight muscles, exhibited in the first 
plan of the cordage of the eye, compressing the globe, so 
equally, as to elongate the eye, and lengthen the axis, so 
much, as to favor the union of the pencils of rays on the 
retina. This could not take place in many aquatic ani- 
mals, in whose eyes the sclerotica is perfect bone. 

Another opinion is, that the eye is at rest in looking at 
near objects, and laboring, when viewing things at a dis- 
tance. Another is of the opinion that the iris contracts, 
and so draws the circular margin of the cornea towards 
the pupil, as to make it more or less convex, according 
to circumstances. A great variety of experiments have 
been instituted, to determine, accurately, whether there 
really is any change made in the length of the axis of the 
eye-ball or not, but none of them can be certainly relied 
upon. A favorite theory has had its advocates, that the 
crystaline lens has an inherent power of altering its de- 
gree of convexity ; and thus accommodates the eye to all 
distances. The truth is, an action takes place in the eye, 
in adapting itself to near and distant objects, which de- 
pends on that vital property of a living system, which no 
theory can reach, and which the deductions of human 
philosophy, can never with certainty explain. 



ANATOMICAL CLASS BOOK. 239 



QUESTIONS 



How many coats has the eye ? 

What is the cornea ? 

How many humors has the eye ? 

What is the office of the lens ? 

What is the retina ? 

What do you understand by the pupil ? 

Where is the iris located ? 

What is the use of the ciliary process ? 

Where is the pigment found ? 

Why is the pupil red in the albino ? 

What is the function of the iris ? 

Why is but one object seen with both eyes ? 

What is the cause of squinting ? 

How are some animals able to see in the dark ? 

W^hy cannot a man see under water? 

Why are convex spectacles necessary for the aged ? 

What causes near-sightedness ? 

On what does the color of the eye depend? 

What is the position of the image on the retina ? 

How does the eye alter its focus ? 

W^iat is the use of the aqueous humor ? 

On what does the brilliancy of the organ depend ? 

Where are the tears secreted ? 

What is the effect of distorting one eye ? 

How many muscles are attached to the globe ? 



240 ANATOMICAL CLASS BOOK. 



P.EELING, OR TOUCH. 

Touch is a sensation excited by the contact of bod- 
ies, by which we are enabled to appreciate their various 
qualities, as hard, soft, — heat, cold, wet and dry. The 
immediate seat of this sense, is at the point where the 
nerves terminate in little papillae, and therefore most per- 
fect at the points of the fingers. This sense is undergoing 
incessant changes, from infancy to age. 

That general sense of feeling over all the surface of the 
body, by which we can designate the forms and other 
characters of substances brought in contact with the skin, 
we define to be perception, • 

SMELLING. 

Perhaps the sense of smelling is of the least conse- 
quence to man, of all his senses : nature designed it and 
placed it as a safeguard over the stomach, — to detect the 
hurtful from the wholesome food, — and in savages it an- 
swers this purpose, being always in requisition. In civil- 
ized life, however, it is of very little consequence. Its 
importance to brutes is manifested continually. 



ANATOMICAL CLASS BOOK. 241 



T A STING. 



This sense resides in the tonguejOn which the gustatory 
nerve terminates, in the form of very small tubercles, be- 
ginning at the point and reaching quite into the throat. By 
it we distinguish certain qualities, as sioeet, sour, hitter, 
acrid, 6lc. Before the sensation is complete, the sub- 
stance is necessarily dissolved in the saliva of the mouth, 
by which means it is uniformly presented to the nervous 
papillae. 



21 



242 ANATOMICAL CLASS BOOK. 



THE GLANDS, 



OR ADENOLOGY. 



Glands are generally round, fatty bodies, placed at short 
distances both internally and externally, — whose function 
is either to secrete a fluid, or change the quality of that 
which has been collected by another gland in the neigh- 
borhood. Thus, the salivary glands about the inside of 
the cheek, and below the tongue, secrete the saliva of the 
mouth. The lachrymal glands secrete the tears, and the 
mucus glands secrete mucus. Their importance in the 
animal economy is very great. Tumefactions, or sudden 
swellings of glands by severe colds, indicate, by the de- 
rangement they cause to other organs, their high con- 
sequence. 

INTERNAL ORGANS, OR SPLANCHNOLOGY. 

Under this division, is embraced the viscera or con- 
tents of the three great cavities, viz, in the head, chest 
and abdomen. Of the contents of the skull, we have al- 
ready treated. 

VISCERA OF THE THORAX. 

Within the thorax or chest which is bounded by the 



ANATOMICAL CLASS BOOK, 243 

neck above and the diaphragm or midrif below, are con- 
tained the following organs, viz ; the pleura, lungs, hearty 
thymus gland, cesophagus, thoracic duct, arch of the aorta, 
branches of the cava, vena azygos, eight pair of nerves and 
part of the sympathetic nerve. 

PLEURA. 

Two membranous sacks are lodged in the chest, one 
on either side, attached closely to the ribs, but their sides 
meeting in the middle, under the breast bone, unite and 
form a partition, called 7ncdiastinum. Thus the chest is 
lined, so that each lung has an independent apartment. 

The heart, enclosed in its case, lies in a triangular 
space between the two lungs, 

DIAPHRAGM. 

This is nearly a horizontal partition between the chest 
and abdomen, and is perfectly muscular. Its border ad- 
heres to the ribs, breast bone and spine. Through it, 
near the spine, are openings for the passage of the swal- 
low, blood-vessels and nerves. 

The diaphragm is a muscle of respiratiom, — rising up- 
ward, as the lungs collapse, and falling down again, as the 
lungs become inflated. 

LUNGS. 

There are two membranous organs, by which breath 
ing is effected. The physiology of the function of the 
lungs has been considered, in detail with the circulation 
of the blood. They are divided into right and left: the 
right lung has three lobes, but the left, only two. They 
seem to be made up of a spongy substance, air tubes and 
blood-vessels. Their use cannot be misapprehended. 



244 ANATOMICAL CLASS BOOK. 

By respiration is meant the ingress of air into the lungs, 
and by erpiration its egress from them. 

Voluntary respiration depends upon the will, when we 
are awake, but spontaneous, is the respiration of sleep. 
It is thought that the exciting cause of the process, is the 
irritation of the nerves in the air cells, which by a consent 
of parts, gains the assistance of the diaphragm and inter- 
costal muscles and ribs, to expel it. The object of respi- 
ration, is the oxygenation of the blood. Though the vital 
temperature of the body cannot be readily accounted for, 
it is generally admitted that heat is developed by the action 
of the atmospheric air on the volume of blood exposed to 
its influence with the air cells. 

As an introduction to a descriptionof the vocal apparatus 
of man, and other animals, it seems necessary, first, to 
explain both the process of breathing, and its necessity, 
in the animal economy : because, in the sequel it will be 
apparent, that without lungs, there could be no voice. 

Such is the constitution of every living creature, that a 
free use of atmospheric air is absolutely necessary for sus- 
taining life. The mere circumstance of being surrounded 
by air is not sufficient; if it were, there would be various 
ingenious devices for maintaining life, after the lungs 
were rendered useless by disease or accident. 

It is absolutely necessary that air should be taken into 
the system, and brought in contact with the moving blood. 
The various modes by which nature has accomplished 
this, in the mechanism of some animals, will now be con- 
sidered. 

If Spallanzani and some others are to be credited, in 
their accounts of what they discovered by the microscope, 
we have the first plan of a breathing structure. Spallan- 
zani, pretended he saw the respiration of animalcules in 
vinegar. They were shaped like stars, and in the centre 
of each were two dark globular spots, one of which he con- 
ceived to be the heart pulsating, and the other the lungs. 



ANATOMICAL CLASS BOOK. 245 

Every two or three seconds, to use his own words, they 
were slowly blown up, three or four times their natural 
size, and then slowly compressed again. A modern phy- 
siologist remarks, that the Abbe must have forgotten him- 
self in assigning them lungs, for they were evidently 
aquatic animals, and therefore did not require them. 

Passing by the microscope let us examine something 
more tangible, — the families of insects. They are so 
organised that in proportion to their bulk, they require a 
prodigious supply of air. The heart is the only percepti- 
ble organ in flies and worms : how their breathing organs 
are constructed, we are totally ignorant. 

But pertaining to that apparatus, the existence of which 
cannot be questioned, are an immense number of air tubes, 
coursing over and through every part of them, distinguish- 
able with the naked eye, resembling white lines. It is 
necessary that these be always distended. They open, 
generally, with free mouths, on the sides of the body, and 
wherever there is a ring or line, it marks the place of one 
of them. 

In worms, it also appears necessary that the air holes or 
spirucula, be perfectly free and open. The moment a little 
varnish is applied, ever so delicately, to the last holes, that 
portion towards the tail is paralyzed. By closing the next 
two, another ring is palsied ; if all but the two last, to- 
wards the head are closed, it still lives, though it cannot 
move : but when the last of the series are closed, it dies 
immediately. 

Some vermin require more air, judging from analogy, 
than others much superior in size. So variously are the 
tubes ramified, that the viscera appears to occupy only 
about one fifth of the whole internal cavity. 

Before insects arrive to their perfect state of existence, 
they are destined to undergo several interesting changes. 
First they are worms, ordinarily of a loathsome and dis- 
31* 



246 ANATOMICAL CLASS BOOK. 

gusting appearance ; and lastly, a beautiful winged insect, 
the object of peculiar admiration. In this change, there 
is nothing discoverable to the philosopher like the death 
and resurrection of the insect, so often the theme of 
writers. It does not die, while undergoing the change, 
if it did, the process would never be perfected : close the 
spiracula and there is forever an end to its existence. 

While the caterpillar crawls on its numerous feet, un- 
der its coarse, hairy skin, it has six legs, inimitably folded 
next the body ; — two pair of wings, that only require the 
sun's rays to a-stonish us with the beauty of their coloring ; 
and a proboscis, nicely packed away, to sip the honey 
which Avill be its future food. The period finally arrives, 
when a development of these embryo organs is about to 
take place. Some inscrutable sensation, of which the 
worm appears to have an instinctive knowledge, as it 
seeks a quiet, safe and warm retreat, gives it a timely 
warning. The old covering becomes dry and dark ; the 
fluids cease to circulate in it, and gradually, as the legs 
and wings gain freedom within, they push it entirely off; 
— thus disentangled, it flits away on its untried wings, 
from flower to flower. 

While the skin was drying, the worm breathed as it 
did before, through the air holes of the old covering. 

Insects, it is supposed, never breathe by the mouth. 
The nymphse of gnats can raise themselves to the surface 
of a pool, and breathe by an orifice in their backs. The 
hydro canthiri breathe by thrusting their tails out of water. 
Bugs, flies and worms whiv^h live in filth, ditches, and 
deep under ground, breathe the pure air which is in their 
air tubes, and when it is exhausted, they travel near 
enough to the surface to replenish their stock. But the 
maggot of tlie cruca labra has the most extraordinary ap- 
paratus imaginable. It shoots from its tail, a tube, resem- 
bling the slides of a spyglass, — one beyond another. 



ANATOMICAL CLASS BOOK. 247 

The last has a star-like tuft on the end, which unfolding 
on the water, enables it, thus buoyed up, to breathe freely, 
while it floats about at pleasure, — in search of food. 

Fishes are without lungs, and yet they require a constant 
supply of air, though in a lesser quantity than animals with 
a double heart. Such is their peculiarity of structure, 
that they breathe a mixture of air and watei together. 
The gills enable them to perform this process. Deprive 
water of its air, and the fish dies as soon as it would out 
of water. The free exposure of the gills to water is not 
sufficient : it is necessary to propel the water through them 
forcibly. If the feathery gills of a small perch could be 
unfolded and spread, it is not improbable that they would 
cover a square yard. This will not appear so extraordinary, 
when it is recollected that the nerve in a dog's nose, is 
spread into so thin a web, that it is computed to be four 
yards square. Observe the wonderful economy of nature ; 
this web is so rolled up, like a scroll of parchment, that it 
could be packed away in a lady's thimble. 

Nearly one third of all the blood is exposed to the ac- 
tion of the air, in the gills, at the same time. The fish 
draws in a mouthfid of water, and with a quick motion, by 
closing the jaws, drives it through the gills, and this im- 
parts vitality, and restores the red color to the dark blood 
of the veins. 

Various tribes of fishes which seek their food in the 
mud, and foetid, turbid water, have a striking provision for 
defending their gills ; otherwise they would become clog- 
ged, and breathing would be interrupted by the very filth 
in which they were actually created to live. Their gills 
are small, and covered by the common skin of the body. 
The water is taken at the mouth, and driven with the 
same force, as in the other case, but emptied through 
holes on each side of the neck, just back of the jaws. 
The force is always sufficient, by dividing the water into 



248 ANATOMICAL CLASS BOOK. 

distinct portions, to keep the openings completely clear. 
In fact, the action is like that of an apothecary's syringe. 
A familiar example of this sort of animal mechanism may 
be seen in the lamprey eel. 

A similar breathing apparatus is provided for shell fishes, 
having, however, an additional contrivance, by which they 
can live a considerable time out of water. Here let the 
mechanism be particularly noticed, and admired too, as 
the first step towards a terrestrial animal. As those in- 
habiting salt water are necessarily exposed, by the reced- 
ing of tides, without a limb to assisl them in regaining 
their home, and so organized with extensive gills, encir- 
cling two thirds the circumference of the shell, that they 
cannot breathe air, their apparently helpless condition has 
been provided for in this interesting manner ; viz. they 
are furnished with a long elastic pipe, which is a reservoir 
for water. At necessary intervals, the fish ejects a drop 
with surprising force, through the fringes of the gills, and 
then remains quiet, till some instinctive sensation warns it 
of the necessity of again working its forcing pump. Being 
cold blooded, that is, having the single heart, one throw 
of the brake suffices for a long time. 

In travelling over a clam bed, at low tide, the tremor 
communicated to the fish, apprises it of approaching dan- 
ger, — and the nearer the observer advances, the more 
distinctly can he witness the amazing projectile force with 
which the clam drives a little column of water up through 
the sand. 

This is only part of the contents of the tube. Nothing 
but continued irritation will induce the clam to part with 
the remainder, — which is noticed, in digging, just as the 
shell is exposed to the light. 

By this reserved fund, it can live many days, in open 
air. It is by this tube of water, that the oyster is kept 
alive in the shops. As the exposure in the open air, 



ANATOMICAL CLASS BOOK. 249 

weakens its system, it recruits itself, by jetting a drop of 
water through its gills. This drop may be seen morning 
after morning, on a dry board : — but when the reservoir 
is wholly exhausted, it opens its shell, fearless of conse- 
quences, and seeks in despair, wherever it can reach, a 
fountain, to replenish its engine : — thus it languishes, 
and at last dies, a protracted death, in search of its ac- 
customed element. 

No class of animals are more wonderful on the other 
hand, than the amphibious. They live alternately in two 
elements, — hearing and seeing tolerably well in both. 
The structure of some of their organs of sense, have 
already been considered. But it is not true, as too gene- 
rally believed, that they alternately respire air and water, 
or a mixture of both. They are cold blooded animals, it 
is true, with a single heart — as, for example, the frog 
and aquatic lizards. The water seems to be their peculiar 
element, but after all, they breathe the air exclusively. 
They constitutionally require only a small quantity of 
oxygen, or vital air, to sustain life, and keep the machinery 
in operation. They have lungs, but they have but a faint re- 
semblance to those having warm blood, with a double heart. 

Their lungs are merely membranous bags or cylinders, 
which in their dry, prepared state, appear like bubbles of 
froth. The next extraordinary circumstance is this — 
that breathing is an act depending on the will ; that is, 
they can breathe regularly, at short intervals, for days 
together, or they can stop the respiratory process for hours, 
or perhaps days, and continue equally vigorous. 

Fishes, we have seen, force the water through their 
gills : the same process of forcing air into these membra- 
nous tubes, is accomplished in amphibious animals, by a 
very little additional mechanism — the mouth acts precisely 
like a bellows. The jaws are grooved above and below, 
that they may be air tight, and a slit, acting like a valve, 
is placed at the root of the tongue, over the wind-pipe 



250 , ANATOMICAL CLASS BOOK. 

leading to the lunors. Let it be recollected that the mouth 
is never opened, except for food : the air is drawn in 
through very small nostrils, which in the frog and neut, 
are not larger than cambric needles. The animal slowly 
draws its mouth full of air, and when sufficiently distend- 
ed, forces it through the valve, by the skin, which looks 
like a pouch under the lower jaw. 

The lungs being full, give additional size to the body. 
The abdominal muscles re-act and slowly press it out 
again, and thus we have an example of the mode by which 
this class of animals breathe. 

If the frog's mouth be kept open with a prop, it will 
inevitably die, as there is no power by which it can inhale 
air, short of the bellows of its jaws. It requires no phi- 
losophy, after becoming acquainted with these interesting 
facts, to account for their large mouths and broad jaws. 
No other shape or structure would so completely consti- 
tute the bellows. 

Neuts, lizards and the camelion's lungs, are cylinders, 
running down the sides of their bodies, the whole length, 
and as they force in the air precisely by the same process, 
it will explain the reason of their appearing fat at one 
time, or thin and lank at another. When irritated, or in 
fear, they blow up their bodies to frightful dimensions, to 
appear more formidable, upon the same instinctive princi- 
ple that cats, dogs, hedgehogs and fowls, bristle up their 
covering at the approach of an enemy, superior to them in 
strength. 

The different colors with which the camelion so readily 
dresses itself, depend on this peculiarity of its lungs. The 
skin is covered with an exquisitely fine covering, like vel- 
vet. If the lungs be filled to a certain extent the swelling 
of the body erects the fleece, so that the manner in which 
the light strikes it, makes the animal appear green, white, 
or of other colors: another blast into the lungs, gives 



ANATOxMICAL CLASS BOOK. 251 

another iaclination to the fleece, and it has another tint. 
When, by irritation, its body is blown up to its greatest 
dimensions, various modifications of these colors are 
exhibited. 

From this tribe of reptiles, the first advance is made 
towards endowing animals with the power of producing 
vocal sounds. The water is only capable of propagating 
a vibration, but that with great certainty and strength, and 
nature has constructed an ear, suited to the element and 
the habits of all aquatic beings. To have bestowed an 
ear, susceptible of receiving the modification of sound, 
would have been superfluous, inasmuch as the modifica- 
tions are alone effected in the vocal box of those breath- 
ing air. 

The atmosphere is the medium of modified sound : it 
is an elastic medium which can be put in motion by the 
vibration of solid bodies. It is a medium, w^hich, when 
set in motion by a mechanical contrivance of the greatest 
apparent simplicity, transmits the wants of animals, in 
what is denominated its natural cry, and in man, expresses 
not only his wants, his pleasures, and his pains, but all his 
thoughts, — because his voice represents ideas. Lan- 
guage, therefore, is the symbol of thought. 

The voice of all animals remains the same throuo-h 
endless generations, unless the vocal apparatuses artificial- 
ly altered. Indeed the vocal organs are so constituted, 
that they admit of little variety in their movements: — 
every succeeding class, however, exhibits an additional 
muscle, a bone, or some difference in the shape of the 
tongue^ g'^'iwg it the power of either making one more 
sound than the race below, or some modulation of the 
original tone. Were it not for this progression in the con- 
trivance, the voice of all animals would be precisely the 
same, like sounding one note continually on a musical 
instrument. 



252 ANATOMICAL CLASS BOOK. 

Let us examine another curious mode of respiration, 
peculiar to birds. Although there is an external resem- 
blance, in the shape of their bones, to quadrupeds, and 
the muscles which move them are similarly arranged, to 
effect a circle of motions, their structure has reference to 
their wafting themselves through the air. 

In the first place, the long bones are without marrow — 
being hollow tubes, filled with air, these actually have 
openings communicating with the lungs. At their further 
extremities they permit the air to circulate into the ends 
of each feather; — and lastly, the body has large apart- 
ments exclusively appropriated for the reception of the 
same air. Their lungs, unlike the light frothy tube of 
reptiles^ is spongy and gorged with blood, and totally un- 
like those belonging to any other animal. In the bird, 
the lungs are open at each end, and are so closely tied 
down to the back bone and ribs, that they admit of little 
or no distention or contraction. 

Their breathing is efi'ected in the following manner; 
viz, the air is drawn into the vacuum caused by the 
pressure of the strong muscles of the abdomen. In other 
words, the weight of the atmosphere forces it in, so 
that the current rushes through the whole length of the 
lungs, where the blood is waiting for its appearance, and 
passes to the extremities of all the bones and feathers. 
Theproper change being wrought in the venous blood, it is 
circulated again to the heart, while the muscles again 
empty the lungs and air cells, contiguous, by a general 
compression of the whole. Here is discoverable the me- 
chanism for producing voice, seen in its elements in the 
frog, improved upon, by additional cords and vibrating 
cartilages, susceptible of receiving a current of air, in a 
manner a little different, to produce one, two or three 
different tones. 

Lastly, nature has effected respiration by a more com- 



ANATOMICAL CLASS BOOK. 253 

plex piece of mechanism, in those animals whose bodies 
are divided into two apartments by the diaphragm. 

A difference of structure does not appear in the air cells 
of the lungs of about forty varieties of animals, including 
man. The only circumstances observable relates to their 
shape and subdivisions, depending on the configuration of 
the cavity in which they are lodged. The human lungs 
are suspended in the chest, much as they are in brutes, 
by the wind-pipe, and so tied down at the upper part of 
the neck, and so carefully fitted to the dimensions of the 
box, in which they are lodged, that no position of the body 
can throw them out of place. There is a right and a left 
lung, perfectly independent of each other, and separated 
by a middle partition. 

Exactly in the centre of this partition, in quadrupeds, 
the heart lies, but in man, it is on the left side, and there- 
fore projects into the cavity of the left lung. They are 
made up of millions of air cells, which are filled at every 
inspiration. The blood, directly from the heart, is thrown 
into them in prodigious quantities, and circulates so mi- 
nutely, that each air cell is completely surrounded by a 
sheet of dark blood. 

VOICE, 

We shall now inspect the contrivance by vv^hich sounds 
are produced by animals. 

By voice animals have the power of making themselves 
understood to their own species — and these sounds are 
either articulate or inarticulate. 

Language is an acquired pouter, having its origin in the 
wants of more than one individual. Man, without socie- 
ty, would only utter a natural cry, which sound would 
express nothing but pain. 

Supposing a human being to have been entirely forsaken 
22 



254 ANATOMICAL CLASS BOOK. 

by those of his species, in that stage of infancy, when he 
could have no recollection of anything pertaining to his 
race, his voice would, in essence, remain the cry of an 
infant, only strengthened in tone, at a particular age, by 
the development of the vocal organs, to their destined 
size. 

But let two individuals be placed together, but without 
communication or knowledge of the existence of beings 
similar to themselves, the natural cry of each would un- 
dergo modifications : the one would make a sound, to 
express a particular sensation, which in time would be un- 
derstood by the other : a repetition of the same note 
would be the sign of that sensation in future. 

An additional sensation, having an intimate connexion 
with the first, would require a variation of tone, — and 
this would also become a symbol of two sensations. Here 
then would be the origin of language. Multiply the spe- 
cies, and each new member of the society would express 
some other sensation or want, by another modification of 
the original cry. Here we discover the certain commence- 
ment of a spoken language ; these diflferent sounds becom- 
ing classified, constitute a dictionary, in which each word 
is the mark or sign of particular sounds; — thus, if an in- 
dividual can imitate the sound, or a series of sounds, he 
masters a language. Let it be remembered that man 
could never arrive to this perfection in sound or language, 
if his vocal organs were not differently constructed from 
brutes. Such is the mechanism of theirs, that so many 
sounds, and no more, can be made ; but in man's organs, 
there is no limitation — no sound appreciable that he can- 
not imitate. 

THE VOCAL BOX OR LARYNX. 

Directly under the integuments on the front side of the 



ANATOMICAL CLASS BOOK. 



255 



neck, is a cartilaginous lube, the trachea or wind-pipe, 
built up of a series of narrow strips, which are portions of 
a ring; therefore, it is always kept free and open. At its 
lower end it divides into two branches, going to the lungs 
on either side, but its upper portion is enlarged, just under 
the chii], and finally opens in common with the tube of 
the stomach and mouth. This enlarged part, quite promi- 
nent in man, is the larynx or vocal organ. 

Several cartilages assist in its formation, viz, the thyroid, 
cricoid, the arytcEnoid and the epiglottis. The cricoid is 
the foundation ; the thyroid is the wall around it ; the ary- 
tgenoid are appendages to the back of the cricoid, and the 
epiglottis is a valve, opening and closing the entrance into 
the wind-pipe, like the valve of a bellows. 

Fig. 96. 

8 Explanation of Figs. 

\ 95. 96. 

j The five cartilages are. 

1. The epiglottis. 

2. The thyroid cartilage. 
.^ 3. the cricoid auxiliary 

"and 

4. The two arytaenoid 
cartilages. 

5. The two superior 
horns of the thyroid cartil- 
age. 

6. The two inferior 
horns. 

7. The suspensory- Hga- 
ment of the os hyoides. 

8. The OS hyoides. 

9. The azygos ligament, 
connecting the os hj^oides 
to the thyroid cartilage. 

10. The two lateral liga- 
ments connecting the horns of the os hyoides to the superior horns 
of the thyroid cartilage. 

One of these diagrams presents a front and the other a back view 
of the larynx or vocal box. The bone of the tongue is seen, like 
half of a hoop marked 8, in both plans. '2 is the front of the thyroid 
cartilage^ felt under the skin — protruding in the form of an irregu- 
lar tumor. The wind-pipe is the tube at the bottom of each larynx. 





256 ANATOMICAL CLASS BOOK. 

The vocal cords — the membranes which vibrate to produce sound, 
as the current of air I'ushes by, ai-e concealed, being placed inside. 
From the remarks in the text, together with the references, a very 
correct idea will be formed of the structure of this curious organ. 
By blowing through the wind-pipe of almost any animal, soon after 
it is slain, provided the larynx has not been injured, the vocal cords 
may be put in motion, and the sound which is produced will bear 
considerable analogy to the natural voice of the animal. 

Within the larynx, and consequently below the valve, 
are four delicate membranes, two on each side, put upon 
the stretch — being in fact, like shelves, — their thin 
edges nearly meeting from the opposite sides, so that there 
is scarcely any space between them. These are the vocal 
cords. 

When the air rushes out from the lungs through the 
wind-pipe, it must obviously pass through the larynx, — in 
doing which it strikes the tense edges of the cords, and 
produces a vibration. This vibratory motion given to the 
current of air, produces sound. In the cavities of the 
bones of the face, forehead and nose, its power is increased, 
and in the mouth it undergoes further modifications, and 
ultimately becomes articulate language. The teeth, 
tongue, lips, nose and fauces have each an influence in 
the production of articulate sounds. Hence grammarians 
have arranged the human voice under the appropriate 
divisions oi guttural, nasalj dental and labial sounds, — 
expressive of the agency which each of these organs exert 
on the original tone. 

Shrillness or roughness of voice depends on the diameter 
of the larynx, — its elasticity, lubricity, and the force with 
which the expired air is propelled through the rima glot- 
tidis, or slit like chink, between the vocal cords. 

Because the larynx is smaller in women, and more elas- 
tic, their voice is of a different character. The breaking 
of the voice, vox rauca, noticeable in boys, at a particu- 
lar age, depends partly on the enlargement of the apart- 



ANATOMICAL CLASS BOOK. 257 

merits within the bones, which generally take place at that 
important crisis of their lives, when the whole constitution 
undergoes a sudden change. 

But the mechanism of voice would have been incom- 
plete, were there not a number of exceedingly delicate 
muscles, which graduate the diameter of the narrow slit 
through which the sound escapes into the mouth. Uncon- 
sciously, they effect the requisite contractions, forever 
varying, according to the rapidity, intensity, or strength of 
the voice, in singing, conversation or declamation. 

Finally, the larynx is a musical wind instrument, of the 
reeded kind, on the principle of the hautboy. The near- 
ness of the vocal cords to each other resembles the reed 
precisely. All the tones of reeded instruments are effect- 
ed by finger holes, — but the tones of the human voice 
are varied by the extrinsic and intrinsic muscles, which 
shorten or elongate the vocal tube. Thus the same re- 
sult is produced by this process, — increasing or diminish- 
ing the diameter of the larynx, that is accomplished in the 
clarionet, bassoon, flute and hautboy, by a graduated 
scale of finger holes. 

Is not this another beautiful mechanical evidence of the 
existence of a Being superior to ourselves 1 



22* 



258 ANATOMICAL CLASS BOOK. 



THE VISCERA, 



OR SPLANCHNOLOGY. 



THE FOOD-PIPE, OR .ESOPHAGUS. 

This is a fleshy tube, going from the back of the mouth 
to the stomach, through the chest, lying in the neck be- 
hind the wind-pipe. Its upper portion is called the pha- 
rynx, or fauces, and its lower, the cardiac extremity, termi- 
nating in the stomach. 

THYMUS GLAND. 

Infants and young children possess a singular gland, 
located just behind the top of the breast bone, which has 
the appellation of thymus gland. In adults, it is obliterated ; 
hence it is supposed to be serviceable only in the early 
stages of our existence. 

THORACIC DUCT. 

duite low in the abdomen is found a white, ex- 
quisitely delicate tube, which runs upward by the side 



ANATOMICAL CLASS BOOK. 259 

of the spine, and finally terminates by communica- 
ting with a large vein in the angle between the neck 
and shoulder, on the left side. All the nutritious sub- 
stance which has been collected from the food in the in- 
testinal tube, — now called chyle, which is white like 
milk, is conducted to this tJioracic duct, and thence car- 
ried on to be poured directly into the circulation, to be- 
come blood. 

ABDOiMEN. 

Bounded by the diaphragm above, the pelvic bones be- 
low and the muscles at the sides, the abdomen is the most 
capacious of all the cavities. Its lining membrane is the 
peritonceum. Various organs, principally subservient to 
digestion, are contained within it. They are the following. 

OMENTUM. 

Vulgarly, the omentum is the cawl, — a sort of apron 
lying in front of the intestines, suspended mainly from the 
stomach. 

LIVER. 

Being the largest and heaviest viscus in the body, the 
liver has also a vast influence on the condition of the 
whole. It is divided into right and left lobes — the right 
is the largest, and occupies the right side, under the ribs. 
The left lobe lies partly over the stomach, in the other 
region. Its use is to secrete bile. 



260 



ANATOMICAL CLASS BOOK. 

Fig- 97. 




ANATOMICAL CLASS BOOK. 261 

Explanation of Fig. 97. 
In this view of the abdomen, d, is the gall-bladder, lying on the 
under side of the liver, the dark mass to v^hich it is attached : h is 
the coronary artery w^hich supplies the stomach, a, b, c, with blood. 
The curve of the stomach is well shown: e, e, the arteries which 
supply the cawl, marked i, i, which falls down from the front of 
the stomach, over the intestines, like an apron : g, a vessel of the 
liver. The pancreas is behind the stomach. 

GALL BLADDER. 

This is attached to the under side of the liver, shaped 
like a shot-pouch, and contains between one and two 
ounces of gall, which is carried to it, as a place of deposit, 
from the liver. A long slender pipe extends from it to 
the duodenum, the first portion of the intestines, into which 
it pours the bile. The use of the bile is to stimulate the 
intestines, in order to keep them at work. 

SPLEEN. 

Anatomists have not discovered the function of this 
organ. Generally, however, it is admitted to be essentially 
serviceable to the stomach. The color is red, somewhat 
like the liver, broad as the paim of the hand, and one or 
two inches thick. It is in contact with the stomach, in 
the left side. 

PANCREAS. 

Behind the stomach, lying directly across the spine, is 
the pancreas, a narrow gland, from eight to ten inches 
long, — which secretes a fluid analogous to the saliva. 
Through a duct, it is carried onward to be mixed with 
the bile in the intestine. It is regarded as an auxiliary 
to digestion. 



•262 ANATOMICAL CLASS BOOK. 



KIDNEYS. 



One of these glands is placed on each side, in the loins, 
near the spine, a little above the hips. From the trunk 
of the aorta, the great artery of the body, two large 
blanches are given off, nearly at right angles, to the kid- 
neys. A quantity of blood is therefore sent directly into 
them, from v^hich the urine is separated, and afterwards 
forced through the ureters^ two tubes the size of a writing 
quill, ten inches or more in length, into the under and 
back part of the bladder. 

The urine is separated from the blood by the extreme- 
ties of the arteries within the substance of the kidney. 
Having remained a while in the bladder, it excites a desire 
to void it, — an action effected chiefly by the muscular 
fibres of the bladder itself, assisted by the abdominal 
muscles. It is prevented from returning from the bladder 
to the kidneys, by a valvular structure within, continually 
closed by the presence of the fluid against the valve. 



ANATOMICAL CLASS BOOK. 263 

Fig. 98, 



Explanation of Fig. 98. 
In this, a and b show the tendinous part of the diaphragm or par- 
tition between the chest and abdomen : d^ the kidney, with its fellow 



264 ANATOMICAL CLASS BOOK. 

opposite ; /, the descending aorta ; /i, an artery given off for the in- 
testinal tube ; i where the great artery divides, to send a branch to 
each leg, g, the ascending great vein, conveying blood to the right 
side of the heart ; c, the capsule, so called, belonging to the kidney, 
the use of which is unknown ; n, the ureter, a tube which conveys 
the urine from the kidney to the under side of the bladder, where it 
terminates : the right ureter is seen on that side, also terminating 
in the bladder, k; m, /, are aiteries; o, is a small artery which runs 
down on the bone, into the pelvis. 



STOMACH. 

Just below the diaphragm, lying nearly horizontally 
across the top of the abdomen, is the stomach, having the 
shape of a shot-pouch, — being large at the extremity on 
the left side, and small where it reaches the right, under 
the margin of the liver. It presents a curve in front and 
shorter one on the back side, where it embraces the spine. 

At the entrance of the oesophagus, the food tube from 
the mouth at the large end of the orifice is called the car- 
diac 07^ijice, — because it was supposed by the early anato- 
mists to be near the heart. Through this the food en- 
ters the stomach ; and where it makes its exit, into the be- 
ginning of the intestine, at the other extremity, the opening 
is the pyloric orifice. A muscle surrounds the neck of 
the stomach, on the inside, which holds a control over the 
contents, allowing it to pass onward, or confining it within, 
according to its state of preparation for digestion. 

INTESTINES. 

With a little variation, the whole extent of the intesti- 
nal tube is six times the length of the body, except in in- 
fancy, when it averages eight times the height of the 
child. 

It is divided into sraall and large intestines. The small 
one is further divided into, first, the duodenum ^ox\\y about 
a foot long, commencing at the stomach : — into this por- 
tion the bile and pancreatic juice is delivered. Secondly, 



ANATOMICAL CLASS BOOK. 



265 



the jejunum, coiled up nearly round the navel : and third- 
ly, the ileoji, the last part of this intestine, joining the 
ccBcum, or beginning of the large tract. Usually the diam- 
eter of this tube is not far from one inch. 

Secondly, the large intestine is divided in the ccEciim, a 
large, irregular membranous sac, with a valve, that ob- 
structs the return of whatever may have once passed it : 
the colon, about two inches in diameter, lying near the 
hip, at the bottom of the abdomen, on the left side, but as- 
cending in a broad curve towards the stomach, crosses 
the spine, and dips down into the right side, — describing 
an arch, — hence this particular part is called the arch of 
the colon. Finally, the rectum is the last division, a foot 
long, terminating externally. 

The inside is beset with the sharp folds of the inner 
membrane, in the form of shelves, exceedingly numerous, 
which are termed valvulcB conniventes. Their express of- 
fice is to prevent a too rapid exit of the food, in its descent, 
before all its nutritious substance has been taken by the 
lacteals. 




-1 
'2 
"3 

•6 



Explanation of Fig. 99. 

1. The oesophagus, or swallow 
perforating 

2. The left opening of the dia- 
phragm. 

3. The cardiac orifice of the 
stomacii. 

4. The small curvature of the 
18 stomach. 
22 5- The great curvature of the 

stomach. 
12 6. The fundus of the stomach. 
18 7. The pyloric orifice. 

8. The duodenum, divided into 
three portions. 
'"l^ 9. The ascending. 

10. The transverse, and 
""20 11 rpj^g descending portion. 
12. Thejejunum,fi)rming three 



23 



266 ANATOMICAL CLASS BOOK. 

fifths of the small intestines, distinguished from the ilium in being 
thicker, more vascular, larger, and having more valves. 

13. The ilium, forming less than two fifths of the small intestines, 
and terminating in the caecum, having two valves at the entrance. 

14. The caecum, the first of the large intestines ; situated in the 
right, having attached to it 

15. The appendix vermiformis. The caecum terminating in 

16. The ascending portion of the colon, which directs its course 
from the c^cum towards the stomach, connected to the right kidney 
by a fold of the peritonaeum. 

17. The arch of the colon, traversing the abdomen beneath the 
stomach. 

18. The descending portion of the colon, directing its course 
towards the left region, connected to the left kidney by a fold of the 
peritoneum. 

19. The sigmoid flexure of the colon, situated in the left iliac re- 
gion, and terminating in 

20. The rectum. 



MESENTERY. 

A duplication or fold of the peritonaeum, drawn out 
as it were from the spine, like a ruffle/Ms the mesentery, 
on the border of which the intestines adhere. By this 
they are supported and kept in place. 

Nearly in the centre, between where the mesentery 
attaches itself to the spine and the intestine, are the me- 
senteric glands, through which the chyle passes in its way 
to the thoracic duct. 

DIGESTION. 

Perhaps no animal process has more deeply engaged 
the attention of physiologists, than digestion. The fol- 
lowing remarks embrace, in a few words, all that is known 
upon the subject. 

Soon after the food has been admitted into the stomach, 
considerably softened by the saliva of the mouth and 
throat, the extremely small arteries spread in the lining 
membrane of the stomach, throw out a fluid which is 
called the gastric juice, which, in addition to the muscular 
action of the stomach, converts the whole mass into a 



ANATOMICAL CLASS BOOK. 267 

greyish paste. It is rolled forward to the pylorus — the 
place of passage into the intestine, where there is mixed 
with it the bile from the gall-bladder, and the juice from 
the pancreas^ both of which dilate it still more. The 
muscular fibres of the first portion being strong, it agitates 
and rolls it about, till it assumes the appearance of a thick 
milky fluid, of the consistence of cream. 

This part of the digestive process, in the first portion of 
the intestine, is termed cJiymifi cation, and the substance 
itself chyme. 

By the peristaltic and vermicular action of the intestine, 
it is carried onward, inch by inch, interrupted by the 
valves, which throw it from side to side, till every particle 
is brought into direct contact with the mouths of the lac- 
ieals, everywhere presented. Thus a prodigious extent 
of absorbent surface is presented to it, through the entire 
course of nearly thirty feet. 

Thus, the further the chyme advances, the more closely 
and certainly is its valuable part taken up by the countless 
millions of lacteal vessels. They terminate in the me- 
senteric glands, where it remains a little time, but for 
what purpose is not precisely understood, and then, by 
another set of ducts, the fluid is conveyed into the thoracic 
duct, to be afterwards carried into the vein, in the neck, 
to be mixed with the blood, and to become blood. 

The final cause, therefore, of digestion, is to elaborate 
a material for making blood, from which the whole system 
is renewed and sustained. Whatever is useless finally 
passes onward into the large intestine, which, in effect, is 
a store-house, — in which its stay is temporary, depending 
on the health, habit and condition of the individual. 

Three hours after the food is masticated, as a general 
rule, it passes through the various changes which have 
been described. 

Three coats are easily shown, in the walls of the 



268 ANATOMICAL CLASS BOOK. 

Stomach and intestines, viz. the peritoneal^ the muscular 
and the mucous. The muscular is a series of fleshy fibres, 
fine as sewing thread, winding round the cylinder; — lon- 
gitudinal fibres are also discoverable ; hence there are two 
particular motions in the intestine. By the contraction of 
the straight fibres, the intestine is gathered up in wrinkles 
at different points, through its whole extent, and then 
elongated again, much like the movement of a worm. By 
the contraction of the others, it is diminished in diameter 
at different sections : — thus they are never at rest, but 
continually moving the chyme from place to place. The 
first motion is the vermicular^ and the second, the peris- 
taltic. 



ANATOMICAL CLASS BOOK. 269 



THE F LUIDS, 



OR HYGROLOGY. 



A VARIETY of fluids are separated from the blood by 
numerous organs, for various purposes, which are divided 
into crudcj sanguineous, li/mphatic, secreted and excremen- 
titious. 

An example of a crude fluid is found in the chyle ; the 
sanguineous in the hlood ; the lymphatic in the lymijhatic 
vessels; and the excrementitious, are all such as are expelled 
from the system as useless. 

Again, the secreted fluids are further subdivided into 
the lacteal, as that in the tubes between the intestines and 
mesenteric glands ; aqueous, in the eye ; mucous, in the 
nose ; albuminous, as the serum of the blood ; oleous, as 
the fat ; and bilious, as exemplified in the bile. 

LYMPHATICS AND THEIR SECRETIONS. 

Whenever a moisture exists, either externally or in the 
obscure cavities of the body, under the skin, among the 
muscles, in the brain, and indeed where any motion is ef- 
fected, the Ji/mphatics exist also, though they are invisible. 
They take up the vapor or fluid and carry it to the tho- 
racic duct, to be mixed with the blood. If any nutritious 

23* 



270 ANATOMICAL CLASS BOOK. 

matter is unnecessarily expended in any of these places, it 
is sure to be collected again and returned to the circulation. 

Without these vessels always on the alert, fluids would 
accumulate beyond the necessities of the organs they 
were designed to assist, which would inevitably abridge 
the freedom of action and produce disease. 

Thus, whatever is superfluous is sent back to the blood, 
from whence, perhaps, in a majority of cases, it was taken, 
and if of no further value, it is thrown into the kidneys, and 
a large portion of it, therefore, is thus conveyed from the 
body, through the agency of the urinary apparatus. 

FLUIDS OF THE CRANIUM. 

A vapor exhales in the ventricles of the brain, secreted 
by the delicate arteries, to prevent an adhesion of the sides, 
and to keep the contents of the head moist. 

OF THE NOSTRILS. 

Part of the mucous in these canals, are the tears passing 
down the lachrymal duct, from the eyes, adverted to in the 
anatomy of the eye. Beside this, a congeries of mucipa- 
rous glands under the lining membrane, also mix their 
secretions with them to preserve the olfactory nerves from 
becoming dry, which would destroy their sensibility. 

No fluid whatever distils from the brain into the nose, 
as sometimes vulgarly supposed. These are the only 
sources, even when in excessive quantity, as when labor- 
ing under a severe cold, whence it arises. 

OF THE MOUTH. 

Under the tip of the tongue, the angle of each jaw, and 
lastly, under the ear, between the jaw and neck, are large 



ANATOMICAL CLASS BOOK. 271 

glands, — each secreting a fluid of the same character, — 
the saliva, in quantity sufficient to soften the food for 
mastication, and to keep the tongue, fauces, sides of 
the mouth and lips moist and flexible. Such is their ac- 
tivity, that several ounces are ordinarily collected in the 
course of one meal. Each gland has a duct leading into 
the mouth: — the motion of the jaws in chewing and 
swallowing contributes to the flowing of the fluid. 



272 



ANATOMICAL CLASS BOOK. 



THE SKIN 



Above the muscles, and directly under the skin, is a 
spongy layer called cellular substance, the cells of which 
are filled with fat. This cellular covering is enornnously 
thick in whales, and denominated the blubber, which 
keeps the animal warm. Above this is the true skin, — 
smooth and delicate on its external surface, but of a looser 
texture on the under side, where it forms a union with the 
cellular substance. This true skin is technically called 
cutis vera. It is profusely supplied with blood vessels, 
and so numerous are its nerves, that the point of a needle 
can no where be inserted without wounding one of them. 

As all the nerves finally run towards the surface of 
the body, it has led some to the opinion that the true skin 
was a tissue of nerves and vessels, so intimately inter- 
woven as to constitute a highly sensitive envelope for the 
body. The color of the true skin is nearly the same in 
all races of men, — being as white in the negro as in the 



European. 



RETA MUCOSUM. 



There is spread over the true skin an extremely tliin 
layer of paint, of the consistence of thin size, — which 
has received the name of rcta mucosum, and on this wholly 
and entirely depends the color or complexion of the indi- 



ANATOMICAL CLASS BOOK. 273 

vidual. In the negro, this mucous paste is jet black; in 
the Indian copper colored ; in the Spaniard yellowish, 
but white in the white variety of our species. This pig- 
ment is constantly flowing out upon the skin, to defend its 
irritable surface against the combined influence of the air, 
light and heat. These agents, however, exert an action 
upon the mucous coloring, which dries, becomes hard and 
insensible, and is continually wearing off", and as con- 
stantly renewed. 

SCARF-SKIN. 

A familiar example of the scarf-skin, the exterior coat 
of all, is observable in blisters. It is totally insensible, 
rough and by no means of a uniform thickness. In the 
palms of the hands and soles of the feet, it becomes prodi- 
giously thickened, to defend the tender parts below. This 
scarf-skin is constantly wearing ofl*, and as constantly re- 
newed, and hence it is inferred that it is really nothing 
more than the rete mucosum, thrown ofl* by the action of 
the excretory vessels. 

The query may arise, why, if this is the case, are not 
the palms of the negro's hands perfectly black? They would 
be so, if the scarf-skin in them had not lost its vitality. 
When the negro has suffered from a severe burn, the 
mouths of the ducts, which poured out the coloring matter, 
are sealed up by the subsequent inflammation, so that no 
more paint is thrown out, — and the scar remains white. 
The reason is plain, — the true skin, which is white, is 
no longer obscured by the black pigment. 

Rouge, pearl powder, cream of almonds, milk of roses, 
cologne, spirit of wine, and, indeed, the endless catalogue 
of cosmetics, which are sold in the shops with the ostensi- 
ble object of beautifying the skin, are abominable impo- 
sitions, which ought to be interdicted by a strict police 
regulation, till the happy period arrives when common 



274 ANATOMICAL CLASS BOOK. 

sense is more frequently exercised on the subject of per- 
sonal appearance. The skin cannot be made permanently 
whiter, — nor can the hair be stained without injuring it; 
— a roseate tint cannot be given to the cheek by any pre- 
paration, that will be abiding. All this class of pretended 
beautifying articles positively injure the skin, leaving it 
rougher ; and in old age, in consequence of their habitual 
application, the face is more thickly wrinkled, and the 
complexion assumes the hard dead color of bronze. Still 
worse, the pores are deranged in their functions, and dis- 
ease may be induced by the absorption of some of the 
ingredients of those noxious importations, which were 
never good for any thing but to fill the manufacturer's 
purse at the expense of those who are willing to be the 
dupes of their own folly. Cold water is truly a cosmetic — 
and should be used exclusively. 

The physiology of the nails, which are supposed to be a 
production of the scarf-skin, — is not well understood. — 
Writers have not given a satisfactory explanation of their 
origin or growth. 

With respect to the hair, its growth bears a striking 
analogy to vegetables, — inasmuch as it rises from a bul- 
bous root, imbedded in the skin, into which a gelatinous 
fluid is secreted. It would be entirely unnecessary to de- 
tail the opinions of authors on the subject, or to be very 
particular in relating our own. Hereafter, the physiology 
of the skin, nails and hair will become the topic of a dis- 
tinct essay, — with reference to the abuses of the toilet. 



ANATOMICAL CLASS BOOK. 275 



QUESTION S 



What is Adenology ? 

What is the use of glands ? 

Where is the diaphragm ? 

What organs are contained within the chest? 

What is the object of respiration ? 

How do insects breathe ? 

Is breathing involuntary in reptiles ? 

Where is the organ of voice located? 

How is the larynx formed? 

Where are the vocal cords found ? 

What musical instrument does the larynx resemble ? 

What is the object of the thoracic duct ? 

How is the abdomen bounded ? 

What is the omentum ? 

Where is the liver placed ? 

Where is the gall bladder found ? 

Is the use of the spleen known ? 

What is the function of the pancreas ? 

Where are the kidneys lodged? 

What is the shape of the stomach ? 

How is digestion performed ? 

What is chymification ? 

What is the use of the saliva? 

How many coats has the stomach ? 

What is hygrology ? 



276 ANATOMICAL CLASS BOOK. 

What are the lymphatics ? 

Is any fluid found in the brain ? 

What organs supply fluid to the mouth ? 

On what does the color of the body depend? 

What do you understand by the true skin ? 

Where is the rete mucosum secreted ? 

Why is a negro black ? 

What is the scarf-skin ? 

How is the hair produced ? 

Are the nails a production of the skin ? 

Where is the sense of touch most perfect ? 

Why are there valves in the intestinal tube ? 

Where is the gastric juice formed ? 

Where are the lacteal vessels ? 

What becomes of the nutritious part of the food ? 

Are there openings to the stomach ? 

What is the use of bile or gall ? 

Of what service is the liver ? 

How are the intestines kept in place ? 

Where is the cellular membrane ? 

Are the lungs separated in the chest ? 

How are the tones of the voice varied? 

What is the glottis? 

What prevents food from falling into the wind-pipe ? 

What is the epiglottis ? 

By what organs is the voice modulated ? 





I N D 


E X. 






Page. 




Page. 


Anatomy, 


1 


Blood, circulation'of. 


115 


Anatomy, comparative, 


2 


Brain, insensible. 


158 


Angiology, . 


2 


Brain of worms. 


. 160 


Adenology, 


2 


Brain, structure of. 


156 


Arm bones, 


26 


Breathing of fishes, 


. 247 


Antagonists, of muscles, 


57 


Breathing of shell fish. 


248 


Absorbents, 


97 


Both eyes see but one object, 232 


Auricles, 


126 


Cylindrical bones, 


2 


Artery, coronary, 


. 131 


Clavicle, 


5 


Alveus communis. 


]92 


Connexion of bones, 


9 


Arteries of the brain. 


. 137 


Cheek bones, . 


16 


Arteries of the face, 


136 


Carpus, . . . 


28 


Arteries of the thigh, 


139 


Corsets, . 


. . 40 


Artery of the arm, 


141 


Cutting teeth. 


41 


Air tubes. 


245 


Chewing tobacco, . 


42 


Auditory nerve. 


. 197 


Catalogue of muscles, . 


59 


Aorta, . 


130 


Cavities of the heart. 


. 122 


Aqueous humor. 


. 216 


Compound lever, 


191 


Abdomen, • . 


258 


Carotid artery. 


. 134 


Bursology, 


2 


Capillaries. . 


140 


Bones in the Skeleton, 


3 


Contraction of arteries. 


. 142 


Bones in the skull, 


4 


Circulation of the blood. 


145 


Bones in the face. 


4 


Crassamentum, 


149 


Bone of the tongue, 


5 


Color of the blood. 


149 


Bones of the trunk, 


5 


Cerebrum, 


. 153 


Bones of the hand. 


6 


Coverings of the brain. 


155 


Bones of the leg, . 


6 


Caterpillar, 


. 246 


Bones of the foot. 


6 


Clam, .... 


248 


Bones of the nose, 


16 


Cause of voice. 


. 257 


Breast bone. 


22 


Cosmetics, . 


273 


Bones of the loins, 


23 


Cochlea, 


. 196 


Busks, 


40 


Coats of the eye, . 


209 


Blood in muscles. 


58 


Ciliary processes. 


. 213 


24 









378 



INDEX. 





Page. 




Page. 


Choroides, 


210 


Heart, shape of, 


122 


Cornea, . 


. 211 


Heart-case, 


132 


Cataract, 


219 


Heart-case, use of, . 


132 


Convex spectacles, 


. 228 


Hearing of insects, 


176 


Concave glasseSj . 


230 


Hydrocanthiri, 


246 


Cross-eye, 


, 233 


Humors of the eye, . 


216 


Distortion of the bones, 


37 


Hair, . . . . 


272 


Double heart. 


. 121 


Instep, . . . . 


32 


Double heart, plan of . 


125 


Involuntary muscles, . 


53 


Diastole of the heart. 


. 130 


Irritability of muscles. 


56 


Dorsal nerves, 


166 


Influence of the nerves. 


59 


Drum of the ear, 


. 182 


Imposition in bone setting. 


107 


Dr Darwin's opinion of 


deaf. 


Internal cords of the heart 


126 


ness, 


192 


Intercostal nerves, 


157 


Diagram of the heart. 


. 147 


Involuntary nerves. 


163 


Dura mater, 


155 


Intestines, 


263 


Diaphragm, 


. 243 


Image inverted in the eye 


, 231 


Deafness, partial, . 


202 


Iris, 


212 


Deafness, permanent, 


. 202 


Joints, 


114 


Epiphises, 


3 


Jugular vein, . 


139 


Enamel of the teeth, 


41 


Knee, security of. 


103 


Extensors of the toes, 


106 


Kidneys, 


261 


Ear, 


. 175 


Lower jaw. 


17 


External ear. 


176 


Ligaments, 


45 


Ear wax. 


. 180 


Ligaments of the knee. 


46 


Eustachian tube, 


185 


Ligaments of the hand. 


47 


Error loci, 


150 


Ligaments of the foot, . 


48 


Ear, diseases of, . 


201 


Lumbar abscess. 


75 


Ear ach. 


. 201 


Lacing, 


77 


Eye, . . 


205 


Latissimus muscle, . 


82 


Flat bones, 


2 


Lesser circulation. 


124 


Finger bones, 


29 


Left heart filled at death. 


124 


Female skeleton. 


36 


Little bones of the ear. 


188 


Friction, prevention of. 


57 


Little brain, 


153 


Face, muscles of. 


60 


Lobes of the brain, . 


154 


Fascia of the arm, 


91 


Lungs, . . . 


243 


Fluids, 


115 


Lizards, aquatic, 


. 249 


Frog's heart, . 


. 126 


Lungs of reptiles. 


249 


Force of the auricle. 


129 


Lungs of frogs. 


250 


Food-pipe, 


. 257 


Language, 


. 253 


Growth of the bones. 


35 


Larynx, 


254 


Greater circulation, 


124 


Liver, 


258 


Glands of the ear tube, 


. 181 


Lens, crystaline, . 


218 


Gall-bladder, 


260 


Myology, 


2 


Globe of the eye, 


. 206 


Metacarpus, 


28 


Hygrology, . 


2 


Muscles, physiology of. 


50 


Hip bones, 


24 


Muscles, number of. 


51 


Hand, bones of. 


28 


Muscles, shape of. 


52 


Heart of vermin. 


. 119 


Muscles, two orders of. 


55 


Heart of fishes, , 


119 


Muscles never weary, 


55 



INDEX. 



279 





Page. 




Page. 


Muscles of the ear, 


64 


Pleura, ... 


148 


Muscles of the neck, 


66 


Pancreas, 


. 260 


Muscles of the jaws, 


66 


Pupils of albinos red, . 


234 


Muscles of the throat, 


70 


Ribs, 


21 


Muscles of the ahdomen, 


72 


Roots of teeth, 


41 


Muscles of the pelvis, 


74 


Round window, 


. 186 


Muscles of the chest, . 


76 


Rete mucosum, 


270 


Muscles of the back, 


80 


Syndesmology, 


2 


Muscles of the arm. 


86 


Splanchnology, 


2 


Muscles of the thigh. 


96 


Skeleton, 


3 


Muscles of the foot. 


104 


Sesamoid bones. 


3 


Motion of the heart. 


123 


Structure of bones, . 


9 


Mechanism of the nerves. 


158 


Seivebone, 


13 


Musical ear, 


200 


Sutures of the head. 


13 


Membrana Nictitans, 


226 


Spine, 


18 


Names ot muscles, 


101 


Shoulder, 


25 


Nerves of the thigh. 


102 


Small waist. 


38 


Notions of the ancients. 


117 


Sugar, effects of on teeth 


42 


Nerves of the heart. 


131 


Suspended animation, . 


58 


Nerves, 


153 


Strength of the right arm 


I, 87 


Nerves of the foot, 


158 


Supinator muscles, . 


92 


Nerves of the arm. 


168 


Sole of the foot, . 


109 


Nerves accompany arterie 


s, 163 


Single heart. 


. 120 


Nine pair of nerves. 


. 164 


Spinal marrow. 


157 


Nerves of the face. 


168 


Sympathetic nerve, 


. 173 


Nerves of the eye. 


169 


Senses, 


175 


Nerve of the tongue, 


171 


Semicircular canal, 


. 187 


Nymphae of gnats. 


246 


Stapes, 


189 


Nerves of a perch. 


247 


Spiracula, 


. 245 


Near sightedness. 


229 


Spallanzani, 


244 


Neuts, 


250 


Spleen, 


. 260 


Osteology, 


2 


Stomach, 


263 


Os frontis. 


10 


Seeing in the dark. 


. 235 


Occipital bone, 


12 


Seeing in water. 


235 


Os hyoides, 


18 


Smelling, 


. 240 


Olfactory nerves, 


167 


Socket of the eye, 


206 


Optic nerves. 


. 167 


Sclerotica, 


. 209 


Oval window, 


186 


Scarf skin, . 


271 


Oyster, how it lives on lac 


d, 248 


Teeth, number of, . 


4 


Omentum, 


258 


Temporal bone, . 


12 


Optic nerve, 


222 


Tear bones. 


17 


Processes, 


3 


Tibiae, 


31 


Palate bones. 


17 


Thigh bone, 


31 


Periosteum, 


34 


Teeth, 


41 


Practice of muscles, 


54 


Tendons, 


57 


Pronator muscles, 


92 


Two sets of blood vessels 


5, 123 


Power of the left heart. 


124 


Tube of the ear, . 


179 


Position of the heart, 


. 133 


Tympanum, 


184 


Primative artery. 


135 


Tasting, 


141 


Pia mater. 


. 156 


Thyroid Cartilage, . 


. 255 



380 



INDEX. 





Page. 




Page. 


Thymus gland, . 


257 


Veins of the leg, 


. 144 


Thoracic duct, 


. 258 


Vitality of the blood, . 


148 


The eye adapts itself to distan- 


Viscera of the chest. 


. 142 


ces, 


. 237 


Voluntary respiration, . 


244 


Tears, 


227 


Vermin, 


245 


True skin, 


. 270 


Voice of animals, 


251 


Upper jaw bones. 


16 


Voice of man. 


. 253 


Vertebrae, 


19 


Vocal strings. 


256 


Voluntary muscles, 


53 


Valves of the intestines. 


. 264 


Ventricles of the heart, 


. 126 


Wall bones, , 


12 


Vena cava, 


127 


Wedge bone, . 


12 


Valves of the heart. 


. 130 


Wrist, bones of. 


27 


Vestibule, 


. 191 


Wisdom teeth, 


41 


Veins, . . , 


143 


Warm blooded animals, 


120 



.46 



^Tr 



mm 



1- 



